Topic 9 · The periodic table — the scripts

What you are deciding: go-ahead for video generation on this topic, card by card.

Out of scope: articles and PP100 items (not on this page).

Here: the intro video, 7 lesson videos (4 marked by the author as “could do without a video”) and the summary video, in teaching order. Each card: the script, the attached question, then the quiz the student meets after the video.

How: tap one button per card. Taps and notes save as you go and are sent; the Notes tab shows what has gone and re-sends.

Intro video · teaches nothing, opens the question105 words · about 0:52

Introduction: The periodic table

Script
SayScreen
Two bottles sit on a shelf: one label reads Co, the other reads CO.[two bottles; the labels]
One holds a hard, gray metal, and the other holds a poisonous gas.[a gray lump; a hazard mark]
Scientists know 118 elements, and here they all are, on one chart.[the whole periodic table slides in]
And from this chart, chemists can say what an element is like, even one nobody has ever held.[a column lights up; a cell at its foot glows]
So how does one small letter tell Co from CO, and how do you read this chart?[the bottles beside the chart; question mark]
To find out, we will look at how chemists write each element, and how the chart lays them all out.[the chart stays]
Okay, so are you ready to learn to read the chart?[the three replies appear]

The ready line's poll — the attached item (no key; the intro teaches nothing)

video

Okay, so are you ready to learn to read the chart?

  1. A Yes, let's go! — Great. Here we go.
  2. B Not sure yet — That's fine. We take the chart one box at a time.
  3. C Let me watch that again — Good idea. Watch it again, then come back.
Answer

No key. A poll: every reply is accepted with its friendly line.

Your note · the intro video
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 1 of 7Author: could do without a video189 words · about 1:34

Chemical symbols: one element or two?

MAT-053 · Chemical symbols — Read a chemical symbol correctly, including applying the capitalisation rule to tell one element from two.

Script
SayScreen
Two bottles sit on a shelf: one label reads Co, the other reads CO.[two bottles; labels Co and CO]
Co is a hard, gray metal, and CO is a poisonous gas.[a gray lump beside the left bottle; a hazard mark beside the right]
So what does the small letter mean?[the o and the O glow; question mark]
It means the short name is one name, not two.[Co underlined as one unit; C and O underlined as two]
Scientists know 118 elements, each made of only one kind of atom.[a row of element names scrolls: cobalt, carbon, oxygen, gold]
Chemists write each element as a short name of one or two letters: C for carbon, Co for cobalt.[C, Co appear under their names]
This short name is called the element's chemical symbol.[chip: CHEMICAL SYMBOL]
The first letter is always a capital, and the second, if there is one, is always small.[Co: the C ringed, the o marked small]
So every capital letter starts a new symbol.[CO: two rings, one on each capital]
Co has one capital letter, so Co names one element: cobalt.[Co; 1 capital; tick; ONE ELEMENT: cobalt]
But CO has two capital letters, so CO names two elements: carbon and oxygen.[CO; 2 capitals; cross; TWO ELEMENTS: carbon, oxygen]
And HF has two capital letters too, so HF names two elements.[HF; 2 capitals; cross; TWO ELEMENTS: hydrogen, fluorine]
But Hg has one capital letter, so Hg names one element.[Hg; 1 capital; tick; ONE ELEMENT: mercury]
So, here's what we've seen. Count the capital letters, and you count the elements.[the rule slide: the five symbols with their rings and ticks; nothing else printed]
So on the shelf, Co is one element, and CO is two symbols written together.[the two bottles; the rings on the capitals]
Okay, now your turn.[closing screen: one line — "Count the capital letters, and you count the elements."]

“Okay, now your turn.” — the attached question

video

A bottle's label reads CO. How many elements does the label CO name?

  1. A one element
  2. B two elements
  3. C three elements
Answer

Key: B — two elements

Every capital letter starts a new symbol.
CO has two capital letters.
So CO names two elements, carbon and oxygen.

Feedback per option

  • A Cobalt's symbol is Co, with a small o; CO has two capitals, so it names two elements.
  • B CO has two capital letters, so CO is two symbols written together: carbon and oxygen.
  • C Three elements would need three capital letters; CO has two, the C and the O.

Quiz after the video — the mastery check, 13 items

Q1recall

Zinc is made of only one kind of atom. What is a substance like zinc called?

  1. A a mixture
  2. B an element
  3. C a compound
Answer

Key: B — an element

Zinc is made of only one kind of atom.
A substance made of only one kind of atom is called an element.
So zinc is an element.

Feedback per option

  • A A mixture holds two or more substances mingled together; zinc holds one kind of atom.
  • B A substance made of only one kind of atom is called an element.
  • C A compound holds two or more kinds of atom joined; zinc holds one kind.
Q2term

The short name of one or two letters that chemists write for an element is called its…

Typed answer

Answer

Accepted: chemical symbol · symbol · a chemical symbol · the chemical symbol · its chemical symbol

Chemists write each element as a short name of one or two letters.
That short name is called the element's chemical symbol.
Q3fluency

How many elements does Sn name?

  1. A one element
  2. B two elements
Answer

Key: A — one element

Count the capital letters in Sn: one, the S.
Every capital letter starts a new symbol, so Sn is one symbol.
So Sn names one element, tin.

Feedback per option

  • A Sn has one capital letter, so Sn is one symbol: the element tin.
  • B Count the capital letters: Sn has one, the S, so Sn is one symbol, tin.
Q4fluency

How many elements does Si name?

  1. A one element
  2. B two elements
Answer

Key: A — one element

Count the capital letters in Si: one, the S.
The i is small, so it belongs to the same symbol.
So Si names one element, silicon.

Feedback per option

  • A Si has one capital letter, so Si is one symbol: the element silicon.
  • B The i is a small letter, not a capital, so Si is one symbol, silicon.
Q5fluency

How many elements does NO name?

  1. A one element
  2. B two elements
Answer

Key: B — two elements

Count the capital letters in NO: two, the N and the O.
Every capital letter starts a new symbol, so NO is two symbols.
So NO names two elements, nitrogen and oxygen.

Feedback per option

  • A The O is a capital letter, so it starts a second symbol: N and O, two elements.
  • B NO has two capital letters, N and O, so NO names two elements: nitrogen and oxygen.
Q6fluency

How many elements does KI name?

  1. A one element
  2. B two elements
Answer

Key: B — two elements

Count the capital letters in KI: two, the K and the I.
Every capital letter starts a new symbol, so KI is two symbols.
So KI names two elements, potassium and iodine.

Feedback per option

  • A The I is a capital letter, so it starts a second symbol: K and I, two elements.
  • B KI has two capital letters, K and I, so KI names two elements: potassium and iodine.
Q7fluency

How many elements does Br name?

  1. A one element
  2. B two elements
Answer

Key: A — one element

Count the capital letters in Br: one, the B.
The r is small, so it belongs to the same symbol.
So Br names one element, bromine.

Feedback per option

  • A Br has one capital letter, so Br is one symbol: the element bromine.
  • B The r is a small letter, so Br is one symbol, bromine.
Q8fluency

How many elements does Cs name?

  1. A one element
  2. B two elements
Answer

Key: A — one element

Count the capital letters in Cs: one, the C.
The s is small, so it belongs to the same symbol.
So Cs names one element, cesium.

Feedback per option

  • A Cs has one capital letter, so Cs is one symbol: the element cesium.
  • B The s is a small letter, so Cs is one symbol, cesium.
Q9fluency

How many elements does HCl name?

  1. A one element
  2. B two elements
Answer

Key: B — two elements

Count the capital letters in HCl: two, the H and the C.
The l is small, so it belongs with the C: Cl.
So HCl is two symbols, hydrogen and chlorine: two elements.

Feedback per option

  • A The C is a capital letter, so it starts a second symbol: H and Cl, two elements.
  • B HCl has two capital letters, H and C, so HCl is two symbols: hydrogen and chlorine.
Q10fluency

How many elements does BN name?

  1. A one element
  2. B two elements
Answer

Key: B — two elements

Count the capital letters in BN: two, the B and the N.
Every capital letter starts a new symbol, so BN is two symbols.
So BN names two elements, boron and nitrogen.

Feedback per option

  • A The N is a capital letter, so it starts a second symbol: B and N, two elements.
  • B BN has two capital letters, B and N, so BN names two elements: boron and nitrogen.
Q11misconception

Amir says: "CO is the chemical symbol for cobalt." Is Amir correct?

  1. A yes
  2. B no
Answer

Key: B — no

A chemical symbol has one capital letter, and its second letter is small.
CO has two capital letters, so CO is two symbols: carbon and oxygen.
Cobalt's symbol is Co, so Amir is not correct.

Feedback per option

  • A CO looks like a two-letter symbol, but a symbol has one capital letter. CO is two symbols, carbon and oxygen; cobalt is Co.
  • B A chemical symbol has one capital letter. CO has two, so CO is two symbols, carbon and oxygen; cobalt's symbol is Co.
Q12fluency

The table gives six elements and their chemical symbols. Which element has the symbol Pb?

elementsymbolzincZnsilverAgnitrogenNleadPbpotassiumKtinSn
  1. A lead
  2. B potassium
  3. C tin
Answer

Key: A — lead

Find the symbol Pb in the table.
The row reads lead.
So Pb is the symbol for lead.

Feedback per option

  • A Find Pb in the table: lead. The symbol comes from lead's old Latin name, plumbum.
  • B Potassium's symbol is K; the table gives Pb for lead.
  • C Tin's symbol is Sn; the table gives Pb for lead.
Q13fluency

The table gives six elements and their chemical symbols. Which is the symbol for silver?

elementsymbolsiliconSisulfurSsilverAgsodiumNacopperCumercuryHg
  1. A Si
  2. B Ag
  3. C S
Answer

Key: B — Ag

Find silver in the table.
The row reads Ag.
So Ag is the symbol for silver.

Feedback per option

  • A Si is silicon's symbol; the table gives Ag for silver.
  • B Find silver in the table: Ag, from silver's old Latin name, argentum.
  • C S is sulfur's symbol; the table gives Ag for silver.
Your note · lesson 1: Chemical symbols: one element or two?
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 2 of 7Author: definitely a video199 words · about 1:40

The periodic table: every element on one chart

MAT-054 · The periodic table organises all known elements — State what the periodic table is and what it organises.

Script
SayScreen
Scientists know 118 elements, and the number of protons decides which element an atom is.[118 in large type; an atom with its nucleus counted]
So each element has its own count of protons, from 1 to 118.[cards with 1, 2, 3 … 118]
Imagine 118 cards, one for each element, tipped out onto a desk.[the cards tumble into a heap]
How would you lay them out so you could find any element fast?[question mark over the heap]
You lay them out in order of their proton count: 1, then 2, then 3, and so on.[cards slide into a row: 1, 2 … ]
The cards run along a row, and a new row starts underneath when the row is full.[row 1 ends at 2; row 2 fills 3 to 10; rows build to 118]
This chart of every known element, one box each, is called the periodic table.[the finished table; chip: PERIODIC TABLE]
Look at carbon's box: the small 6 at the top is there because every carbon atom has 6 protons.[carbon's box enlarged; the 6 glows]
On the table, this number of protons is called the element's atomic number.[chip: ATOMIC NUMBER = number of protons]
The makers ended each row so that elements that behave alike landed in one column.[row 1's two boxes; one column lights up top to bottom]
So, the periodic table is a chart of every known element, one box per element.[the rule slide: the table with carbon's box ringed; chips PERIODIC TABLE, ATOMIC NUMBER; nothing else printed]
The boxes run in order of atomic number, and the atomic number is the number of protons.[the path along the rows; carbon's 6 glows]
So the cards, laid out in order row by row, make the periodic table.[the heap becomes the table]
Okay, now your turn.[closing screen: bullets — • The periodic table: every known element, one box each • The boxes run in order of atomic number, the number of protons]

“Okay, now your turn.” — the attached question

video

The periodic table lays out all 118 elements, one box each. In what order do the boxes run?

  1. A the elements' names, A to Z
  2. B how common each element is
  3. C the number of protons
Answer

Key: C — the number of protons

Each box carries its element's count of protons.
The boxes run 1, 2, 3 and on to 118.
So the table runs in order of the number of protons.

Feedback per option

  • A The boxes are not sorted by name; they run 1, 2, 3 by proton count.
  • B How common an element is plays no part; the boxes run by proton count.
  • C The boxes run 1, 2, 3 and on to 118: in order of the number of protons, the atomic number.

Quiz after the video — the mastery check, 10 items

Q1recall

What decides which element an atom is?

  1. A the number of protons in it
  2. B the number of neutrons in it
  3. C the size of the atom
Answer

Key: A — the number of protons in it

Every atom with 6 protons is carbon, and every atom with 7 is nitrogen.
So the number of protons decides which element an atom is.

Feedback per option

  • A The number of protons decides which element an atom is.
  • B Neutrons do not decide the element; the protons do.
  • C Size does not decide the element; the number of protons does.
Q2term

The chart of every known element, one box per element, in order of proton count, is called the…

Typed answer

Answer

Accepted: periodic table · the periodic table · a periodic table

Every known element has one box, and the boxes run in order of proton count.
That chart is called the periodic table.
Q3term

On the periodic table, the number of protons in an atom of an element is called the element's…

Typed answer

Answer

Accepted: atomic number · the atomic number · its atomic number

Each box carries a small number at the top: the number of protons.
On the table, that number is called the atomic number.
Q4what

One box on the periodic table is for…

  1. A one element
  2. B one compound
Answer

Key: A — one element

The periodic table is a chart of every known element.
Each element has one box.
So one box is for one element.

Feedback per option

  • A The periodic table has one box per element: 118 boxes for 118 elements.
  • B Compounds have no box: the table holds elements only.
Q5what

In what order do the boxes of the periodic table run?

  1. A in alphabetical order of name
  2. B in order of atomic number
Answer

Key: B — in order of atomic number

Each box carries an atomic number: the number of protons.
The boxes run 1, 2, 3 and on to 118.
So the order runs by atomic number.

Feedback per option

  • A The names are not in alphabetical order: aluminum, 13, sits well after boron, 5. The boxes run by atomic number.
  • B The boxes run 1, 2, 3 … 118: in order of atomic number, the number of protons.
Q6what

Zinc's box on the periodic table carries the atomic number 30. How many protons does one zinc atom have?

Typed answer

Answer

Accepted: 30 · 30 protons · thirty

The atomic number is the number of protons.
Zinc's atomic number is 30.
So one zinc atom has 30 protons.
Q7what

Where on the periodic table do elements that behave alike sit?

  1. A next to each other in the same row
  2. B at the two ends of the same row
  3. C in the same column
Answer

Key: C — in the same column

The table's makers ended each row so that elements that behave alike landed under each other.
So elements that behave alike sit in the same column.

Feedback per option

  • A Neighbors in a row can be very different: sodium, silicon and chlorine sit side by side. Look-alikes sit in the same column.
  • B The two ends of a row are unlike each other; look-alikes sit in the same column.
  • C The makers ended each row so that elements that behave alike landed in the same column.
Q8misconception

Dara says: "Water has its own box on the periodic table." Is Dara correct?

  1. A yes
  2. B no
Answer

Key: B — no

The periodic table has one box per element.
Water is a compound: hydrogen and oxygen atoms joined.
Hydrogen and oxygen have boxes, and water does not, so Dara is not correct.

Feedback per option

  • A Water is common, but it is a compound, not an element. The table holds elements only: hydrogen and oxygen have the boxes.
  • B The table holds elements only. Water is a compound of hydrogen and oxygen, and those two elements have the boxes.
Q9transfer

In 2010 scientists made a new element whose atoms have 117 protons. Where did its box go on the periodic table?

  1. A at the far right end of the top row
  2. B between the boxes for 116 and 118
  3. C in a new row of its own
Answer

Key: B — between the boxes for 116 and 118

The atomic number is the number of protons: 117.
The boxes run in order of atomic number.
So the new box sits between 116 and 118.

Feedback per option

  • A The top row holds atomic numbers 1 and 2; 117 belongs in order, between 116 and 118.
  • B The boxes run in order of atomic number, so 117 sits between 116 and 118.
  • C The boxes run in order of atomic number, so 117 takes the gap between 116 and 118, in the same row.
Q10what

How many boxes does the periodic table hold?

Typed answer

Answer

Accepted: 118 · 118 boxes · 118 elements

Scientists know 118 elements.
The periodic table has one box per element.
So the table holds 118 boxes.
Your note · lesson 2: The periodic table: every element on one chart
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 3 of 7Author: could do without a video186 words · about 1:33

Find an element and read its box

MAT-058 · Look up an element's symbol and atomic number — Find a named element on the periodic table and read off its symbol and atomic number.

Script
SayScreen
A student is asked for the symbol of calcium, and for the number of protons in one calcium atom.[the question on a card]
She has never memorized calcium, but the periodic table lies in front of her.[the whole table slides in]
Where does she look, and what does she read?[question mark]
Every box holds three things: the atomic number at the top, the symbol in the middle, and the name underneath.[one box enlarged; the three parts lit in turn]
She finds the name calcium: its box sits in row 4, second from the left.[the table; the finger runs along row 4; calcium's box ringed]
She reads the symbol in the middle: Ca.[calcium's box enlarged; the Ca glows]
She reads the atomic number at the top: 20.[the 20 glows]
The atomic number is the number of protons, so one calcium atom has 20 protons.[label: 20 PROTONS]
Now consider zinc: she finds the name, reads Zn, reads 30, so 30 protons.[zinc's box enlarged; Zn, then 30, lit as read]
And chlorine: she finds the name, reads Cl, reads 17, so 17 protons.[chlorine's box enlarged; Cl, then 17, lit as read]
So, to look an element up, find its name on the periodic table, read the symbol in the middle of its box, and read the atomic number at the top.[the rule slide: the calcium box with its three parts lit; nothing else printed]
So her answer is Ca, atomic number 20, and 20 protons, all read off the table.[the question card, answered]
Okay, now your turn.[closing screen: bullets — • Find the element's name on the table • Read the symbol in the middle of its box • Read the atomic number at the top]

“Okay, now your turn.” — the attached question

video

Calcium's box on the periodic table shows Ca in the middle and 20 at the top. What does the 20 mean?

  1. A 20 protons in each atom
  2. B 20 boxes before calcium
  3. C 20 letters in its name
Answer

Key: A — 20 protons in each atom

The number at the top of a box is the atomic number.
The atomic number is the number of protons.
So every calcium atom has 20 protons.

Feedback per option

  • A The number at the top is the atomic number, the number of protons: 20 protons in each calcium atom.
  • B The boxes do run in order, but the number at the top is the number of protons.
  • C The number at the top has nothing to do with the name; it is the number of protons.

Quiz after the video — the mastery check, 13 items

Q1recall

On the periodic table, what is an element's atomic number?

  1. A the number of boxes before it in its row
  2. B the number of protons in its atoms
  3. C its place in the alphabet
Answer

Key: B — the number of protons in its atoms

Each box carries a small number at the top.
That number is the number of protons in an atom of the element.
It is called the atomic number.

Feedback per option

  • A The boxes run in order of the number, but the number itself is the proton count.
  • B The atomic number is the number of protons in an atom of the element.
  • C The order is not alphabetical; the atomic number is the number of protons.
Q2scaffold

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find magnesium. Which symbol is in its box?

3Lilithium4Beberyllium11Nasodium12Mgmagnesium19Kpotassium20Cacalcium12234part of the periodic table:groups 1–2, periods 2–4

Typed answer

Answer

Accepted: Mg

Find the name magnesium: row 3, second box.
The symbol in the middle of its box is Mg.
Q3scaffold

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Read the small number at the top of magnesium's box. What is magnesium's atomic number?

3Lilithium4Beberyllium11Nasodium12Mgmagnesium19Kpotassium20Cacalcium12234part of the periodic table:groups 1–2, periods 2–4

Typed answer

Answer

Accepted: 12 · twelve

Find magnesium's box: row 3, second box.
The small number at the top is 12.
So magnesium's atomic number is 12.
Q4scaffold

Your answer to the last question was magnesium's atomic number. How many protons does one magnesium atom have?

Typed answer

Answer

Accepted: 12 · 12 protons · twelve

The atomic number is the number of protons.
Magnesium's atomic number is 12.
So one magnesium atom has 12 protons.
Q5bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find phosphorus. Type its symbol.

5Bboron6Ccarbon7Nnitrogen8Ooxygen9Ffluorine10Neneon13Alaluminum14Sisilicon15Pphosphorus16Ssulfur17Clchlorine18Arargon31Gagallium32Gegermanium33Asarsenic34Seselenium35Brbromine36Krkrypton131415161718234part of the periodic table: groups 13–18, periods 2–4

Typed answer

Answer

Accepted: P

Find the name phosphorus: row 3, under the column numbered 15.
The symbol in the middle of its box is P.
Q6bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find chromium. Type its atomic number.

21Scscandium22Tititanium23Vvanadium24Crchromium25Mnmanganese26Feiron39Yyttrium40Zrzirconium41Nbniobium42Momolybdenum43Tctechnetium44Ruruthenium72Hfhafnium73Tatantalum74Wtungsten75Rerhenium76Ososmium57–71345678456part of the periodic table: groups 3–8, periods 4–6

Typed answer

Answer

Accepted: 24 · twenty-four · twenty four

Find the name chromium: row 4, under the column numbered 6.
The small number at the top of its box is 24.
So chromium's atomic number is 24.
Q7bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find bromine. Type its symbol.

31Gagallium32Gegermanium33Asarsenic34Seselenium35Brbromine36Krkrypton49Inindium50Sntin51Sbantimony52Tetellurium53Iiodine54Xexenon81Tlthallium82Pblead83Bibismuth84Popolonium85Atastatine86Rnradon131415161718456part of the periodic table: groups 13–18, periods 4–6

Typed answer

Answer

Accepted: Br

Find the name bromine: row 4, under the column numbered 17.
The symbol in the middle of its box is Br.
Q8bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find tin. Type its atomic number.

27Cocobalt28Ninickel29Cucopper30Znzinc31Gagallium32Gegermanium45Rhrhodium46Pdpalladium47Agsilver48Cdcadmium49Inindium50Sntin77Iriridium78Ptplatinum79Augold80Hgmercury81Tlthallium82Pblead91011121314456part of the periodic table: groups 9–14, periods 4–6

Typed answer

Answer

Accepted: 50 · fifty

Find the name tin: row 5, under the column numbered 14.
The small number at the top of its box is 50.
So tin's atomic number is 50.
Q9bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find barium. How many protons does one barium atom have?

19Kpotassium20Cacalcium37Rbrubidium38Srstrontium55Cscesium56Babarium87Frfrancium88Raradium124567part of the periodic table:groups 1–2, periods 4–7

Typed answer

Answer

Accepted: 56 · 56 protons · fifty-six

Find the name barium: row 6, second box.
The atomic number at the top of its box is 56.
The atomic number is the number of protons, so one barium atom has 56 protons.
Q10bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Find gallium. Type its symbol.

5Bboron6Ccarbon13Alaluminum14Sisilicon27Cocobalt28Ninickel29Cucopper30Znzinc31Gagallium32Gegermanium45Rhrhodium46Pdpalladium47Agsilver48Cdcadmium49Inindium50Sntin910111213142345part of the periodic table: groups 9–14, periods 2–5

Typed answer

Answer

Accepted: Ga

Find the name gallium: row 4, under the column numbered 13.
The symbol in the middle of its box is Ga.
Q11bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Which element has the atomic number 47? Type its name.

25Mnmanganese26Feiron27Cocobalt28Ninickel29Cucopper30Znzinc43Tctechnetium44Ruruthenium45Rhrhodium46Pdpalladium47Agsilver48Cdcadmium75Rerhenium76Ososmium77Iriridium78Ptplatinum79Augold80Hgmercury789101112456part of the periodic table: groups 7–12, periods 4–6

Typed answer

Answer

Accepted: silver

Find the small number 47 at the top of a box: row 5, under the column numbered 11.
The name under the symbol Ag is silver.
So silver has the atomic number 47.
Q12bare

In this part of the periodic table, each box shows the element's atomic number at the top, its symbol in the middle, and its name below. Which element has the atomic number 33? Type its name.

5Bboron6Ccarbon7Nnitrogen8Ooxygen9Ffluorine10Neneon13Alaluminum14Sisilicon15Pphosphorus16Ssulfur17Clchlorine18Arargon31Gagallium32Gegermanium33Asarsenic34Seselenium35Brbromine36Krkrypton49Inindium50Sntin51Sbantimony52Tetellurium53Iiodine54Xexenon1314151617182345part of the periodic table: groups 13–18, periods 2–5

Typed answer

Answer

Accepted: arsenic

Find the small number 33 at the top of a box: row 4, under the column numbered 15.
The name under the symbol As is arsenic.
So arsenic has the atomic number 33.
Q13misconception

Tess reads the number 22 at the top of titanium's box. She says: "So every titanium atom has 22 protons." Is Tess correct?

  1. A yes
  2. B no
Answer

Key: A — yes

The number at the top of a box is the element's atomic number.
The atomic number is the number of protons in each atom of the element.
Titanium's is 22, so every titanium atom has 22 protons, and Tess is correct.

Feedback per option

  • A The number at the top of a box is the atomic number, and the atomic number is the number of protons: 22 protons in every titanium atom.
  • B The 22 is not a mass or a count of anything else. It is titanium's atomic number, the number of protons in every titanium atom.
Your note · lesson 3: Find an element and read its box
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 4 of 7Author: definitely a video200 words · about 1:40

Metals, nonmetals and metalloids

MAT-056 · Metals, nonmetals, and metalloids — Classify an element as a metal, nonmetal, or metalloid based on its physical properties.

Script
SayScreen
Here on a bench are a strip of copper, a lump of sulfur and a chip of silicon.[the three samples, labeled]
The copper is shiny, bends without breaking, and lights a bulb.[a hand bends the strip; the bulb lights]
The sulfur is dull, crumbles, and leaves the bulb dark.[the lump crumbles; the bulb dark]
The silicon looks shiny, but shatters like glass, and the bulb glows faintly.[the chip shatters; a faint glow]
How many kinds of element are on the bench?[question mark over the three]
There are three kinds.[three empty rows appear]
To sort them, ask three questions: is it shiny, does it conduct electricity, and does it bend without breaking?[three question chips: SHINY? CONDUCTS? BENDS?]
Copper answers yes, yes, yes: an element like copper is called a metal.[copper's row: yes yes yes; chip: METAL]
But sulfur answers no, no, no: an element like sulfur is called a nonmetal.[sulfur's row: no no no; chip: NONMETAL]
But silicon answers yes, a little, and no: an element with some of a metal's properties and some of a nonmetal's is called a metalloid.[silicon's row: yes, a little, shatters; chip: METALLOID]
Scientists call the three properties luster, conductivity and malleability.[the three labels appear under the three questions]
So, a metal is shiny, conducts electricity, and bends without breaking.[the rule slide: the three-row table; chips METAL, NONMETAL, METALLOID; nothing else printed]
A nonmetal is dull, does not conduct electricity, and crumbles or is a gas.[sulfur's row glows]
A metalloid looks shiny but shatters, and conducts electricity only a little.[silicon's row glows]
So copper is a metal, sulfur is a nonmetal, and silicon is a metalloid.[the three samples with their kinds]
Okay, now your turn.[closing screen: bullets — • Metal: shiny, conducts electricity, bends without breaking • Nonmetal: dull, does not conduct, crumbles or is a gas • Metalloid: looks shiny but shatters, conducts only a little]

“Okay, now your turn.” — the attached question

video

A chip of silicon looks shiny, but it shatters and conducts electricity only a little. Which kind of element is silicon?

  1. A a metal
  2. B a metalloid
  3. C a nonmetal
Answer

Key: B — a metalloid

Silicon looks shiny, but it shatters and conducts electricity only a little.
That is some of each kind's properties.
So silicon is a metalloid.

Feedback per option

  • A A metal bends without breaking and conducts well; the silicon shatters.
  • B Some of a metal's properties and some of a nonmetal's: silicon is a metalloid.
  • C A nonmetal is dull; the silicon looks shiny.

Quiz after the video — the mastery check, 14 items

Q1recall

Which of these is a physical property of a piece of tin?

  1. A it is shiny
  2. B it is an element
  3. C it has 50 protons in each atom
Answer

Key: A — it is shiny

A physical property is something you can observe or measure about a material without changing it into anything else.
You can see that the tin is shiny.
So shiny is a physical property.

Feedback per option

  • A Shiny is something you observe about the tin without changing it: a physical property.
  • B Being an element says what kind of substance tin is, not a property you observe or measure.
  • C The proton count names the element; it is not something you observe or measure about the piece.
Q2recall

A conductor is placed in a circuit with a bulb. What happens?

  1. A the bulb stays dark
  2. B the bulb lights
Answer

Key: B — the bulb lights

A conductor lets electricity pass through it easily.
The current runs through the conductor to the bulb.
So the bulb lights.

Feedback per option

  • A A conductor lets electricity pass through it easily, so the current reaches the bulb.
  • B A conductor lets electricity pass through it easily, so the bulb lights.
Q3term

An element that is shiny, conducts electricity, and bends without breaking is called a…

Typed answer

Answer

Accepted: metal · a metal

Shiny, conducts electricity, bends without breaking: yes to all three questions.
An element with those three properties is called a metal.
Q4term

An element that is dull, does not conduct electricity, and crumbles or is a liquid or a gas is called a…

Typed answer

Answer

Accepted: nonmetal · a nonmetal · non-metal · a non-metal

Dull, no current, and it crumbles or is a liquid or a gas: no to all three questions.
An element with those properties is called a nonmetal.
Q5term

An element that looks shiny but shatters, and conducts electricity only a little, is called a…

Typed answer

Answer

Accepted: metalloid · a metalloid

Shiny like a metal, but it shatters and conducts only a little: some of each kind's properties.
An element like that is called a metalloid.
Q6fluency

The table gives one element's answers to the three sorting questions. Which kind of element is iron?

elementshiny?conducts electricity?bends without breaking?ironyesyesyes
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Iron is shiny, conducts electricity, and bends without breaking.
Yes to all three questions makes a metal.
So iron is a metal.

Feedback per option

  • A Yes, yes, yes: iron is a metal.
  • B A nonmetal is dull and does not conduct; iron is shiny and conducts.
  • C A metalloid shatters and conducts only a little; iron bends and conducts well.
Q7fluency

The table gives one element's answers to the three sorting questions. Which kind of element is phosphorus?

elementshiny?conducts electricity?bends without breaking?phosphorusno, dullnono
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Phosphorus is dull, does not conduct electricity, and crumbles.
No to all three questions makes a nonmetal.
So phosphorus is a nonmetal.

Feedback per option

  • A A metal is shiny and conducts; phosphorus is dull and does not conduct.
  • B Dull, no current, crumbles: phosphorus is a nonmetal.
  • C A metalloid looks shiny; phosphorus is dull.
Q8fluency

The table gives one element's answers to the three sorting questions. Which kind of element is germanium?

elementshiny?conducts electricity?bends without breaking?germaniumyesonly a littleno
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: C — metalloid

Germanium is shiny, conducts electricity only a little, and shatters.
Some of a metal's properties and some of a nonmetal's makes a metalloid.
So germanium is a metalloid.

Feedback per option

  • A A metal bends and conducts well; germanium shatters and conducts only a little.
  • B A nonmetal is dull; germanium is shiny.
  • C Shiny, but it shatters and conducts only a little: germanium is a metalloid.
Q9fluency

The table gives one element's answers to the three sorting questions. Which kind of element is chlorine?

elementshiny?conducts electricity?bends without breaking?chlorineno, a gasnono
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Chlorine is a gas, so it is not shiny and cannot bend, and it does not conduct electricity.
No to all three questions makes a nonmetal.
So chlorine is a nonmetal.

Feedback per option

  • A A metal is a shiny solid that conducts; chlorine is a gas that does not.
  • B A gas: not shiny, no bending, no current, so chlorine is a nonmetal.
  • C A metalloid is a shiny solid that shatters; chlorine is a gas.
Q10fluency

The table gives one element's answers to the three sorting questions. Which kind of element is titanium?

elementshiny?conducts electricity?bends without breaking?titaniumyesyesyes
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Titanium is shiny, conducts electricity, and bends without breaking.
Yes to all three questions makes a metal.
So titanium is a metal.

Feedback per option

  • A Yes, yes, yes: titanium is a metal.
  • B A nonmetal is dull and does not conduct; titanium is shiny and conducts.
  • C A metalloid shatters; titanium bends without breaking.
Q11fluency

The table gives one element's answers to the three sorting questions. Which kind of element is antimony?

elementshiny?conducts electricity?bends without breaking?antimonyyesonly a littleno
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: C — metalloid

Antimony is shiny, conducts electricity only a little, and shatters.
Some of each kind's properties makes a metalloid.
So antimony is a metalloid.

Feedback per option

  • A A metal bends and conducts well; antimony shatters and conducts only a little.
  • B A nonmetal is dull; antimony is shiny.
  • C Shiny, but it shatters and conducts only a little: antimony is a metalloid.
Q12fluency

The table gives one element's answers to the three sorting questions. Which kind of element is bromine?

elementshiny?conducts electricity?bends without breaking?bromineno, a dull liquidnono
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Bromine is a dull liquid, so it is not shiny and cannot bend, and it does not conduct electricity.
No to all three questions makes a nonmetal.
So bromine is a nonmetal.

Feedback per option

  • A A metal is a shiny solid that conducts; bromine is a dull liquid that does not.
  • B A dull liquid, no current, no bending: bromine is a nonmetal.
  • C A metalloid is a shiny solid that shatters; bromine is a dull liquid.
Q13misconception

Lior says: "Every shiny element is a metal." Is Lior correct?

  1. A yes
  2. B no
Answer

Key: B — no

A metal answers yes to all three questions: shiny, conducts electricity, bends without breaking.
Silicon is shiny but shatters and conducts only a little, so silicon is a metalloid.
So a shiny element is not always a metal, and Lior is not correct.

Feedback per option

  • A Shiny alone does not make a metal. Silicon is shiny, yet it shatters and conducts only a little, so silicon is a metalloid.
  • B Silicon is shiny, yet it shatters and conducts only a little, so silicon is a metalloid. Shiny alone does not make a metal.
Q14fluency

The table gives one element's answers to the three sorting questions. Which kind of element is nickel?

elementshiny?conducts electricity?bends without breaking?nickelyesyesyes
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Nickel is shiny, conducts electricity, and bends without breaking.
Yes to all three questions makes a metal.
So nickel is a metal.

Feedback per option

  • A Yes, yes, yes: nickel is a metal.
  • B A nonmetal is dull and does not conduct; nickel is shiny and conducts.
  • C A metalloid shatters and conducts only a little; nickel bends and conducts well.
Your note · lesson 4: Metals, nonmetals and metalloids
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 5 of 7Author: could do without a video200 words · about 1:40

The staircase: where each kind sits

MAT-057 · Find the metal/nonmetal/metalloid region on the table — Classify an element as metal, nonmetal, or metalloid by locating it relative to the staircase on the periodic table.

Script
SayScreen
Here is the periodic table with the metals and the nonmetals shaded.[the shaded table builds: metals, then nonmetals; the six cells between them stay white]
Metals fill the left side and the middle, and nonmetals sit at the right.[the pale region pulses; then the darker right]
A heavy zigzag line runs between them, like a staircase.[the zigzag draws itself from boron down to tellurium]
Often there is no sample to test, only a name on the table.[the three question chips fade; the table stays]
So where do the metalloids sit?[question mark on the band]
They sit along the zigzag line.[the six white cells pulse]
The heavy zigzag line is called the staircase, and it is where the metals end and the nonmetals begin.[chip: STAIRCASE]
Vanadium sits to the left of the staircase, so vanadium is a metal.[V ringed; label METAL]
But bromine sits to the right of the staircase, so bromine is a nonmetal.[Br ringed; label NONMETAL]
But arsenic sits with the staircase running down its side, so arsenic is a metalloid.[As ringed; the line beside it glows; label METALLOID]
And potassium, far to the left, is a metal, and iodine, to the right, is a nonmetal.[K ringed, METAL; I ringed, NONMETAL]
There are two exceptions: hydrogen, at the top left, is a nonmetal, and aluminum touches the staircase but is a metal.[H and Al marked with pointers]
So, read the element's position against the staircase.[the rule slide: the shaded table with the staircase glowing; nothing else printed]
Metals sit to the left of the staircase, nonmetals to the right, and metalloids along it.[the three regions pulse in turn]
So the metalloids sit in the darkest band, along the staircase itself.[the six white cells shade in darkest; the band glows]
Okay, now your turn.[closing screen: one line — "Metals sit to the left of the staircase, nonmetals to the right, and metalloids along it."]

“Okay, now your turn.” — the attached question

video

Bromine sits to the right of the staircase on the periodic table. Which kind of element is bromine?

  1. A a metal
  2. B a metalloid
  3. C a nonmetal
Answer

Key: C — a nonmetal

Read the position against the staircase.
Bromine sits to the right of the staircase.
Elements to the right of the staircase are nonmetals.

Feedback per option

  • A Metals sit to the left of the staircase; bromine sits to the right.
  • B Metalloids sit where the staircase runs down their side; bromine sits clear of it, to the right.
  • C Bromine sits to the right of the staircase, so bromine is a nonmetal.

Quiz after the video — the mastery check, 12 items

Q1recall

Which kind of element looks shiny but shatters, and conducts electricity only a little?

  1. A a metal
  2. B a nonmetal
  3. C a metalloid
Answer

Key: C — a metalloid

A metal is shiny, conducts well and bends.
A nonmetal is dull and does not conduct.
Shiny but shatters, and conducts only a little, is a metalloid.

Feedback per option

  • A A metal bends without breaking and conducts electricity well.
  • B A nonmetal is dull, not shiny.
  • C A metalloid looks shiny but shatters, and conducts electricity only a little.
Q2fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe91011121314151617182345part of the periodic table: groups 9–18, periods 2–5
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Find the ringed cell: atomic number 28, in row 4.
The staircase runs several cells to its right, so the cell sits to the left of the staircase.
Elements to the left of the staircase are metals.

Feedback per option

  • A The ringed cell, atomic number 28, sits to the left of the staircase: a metal.
  • B Nonmetals sit to the right of the staircase; this cell sits to its left.
  • C The staircase does not run down this cell's side; the cell sits well to the left.
Q3fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar29Cu30Zn31Ga32Ge33As34Se35Br36Kr47Ag48Cd49In50Sn51Sb52Te53I54Xe79Au80Hg81Tl82Pb83Bi84Po85At86Rn111213141516171823456part of the periodic table: groups 11–18, periods 2–6
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Find the ringed cell: atomic number 35, in row 4.
The staircase runs to its left, so the cell sits to the right of the staircase.
Elements to the right of the staircase are nonmetals.

Feedback per option

  • A Metals sit to the left of the staircase; this cell sits to its right.
  • B The ringed cell, atomic number 35, sits to the right of the staircase: a nonmetal.
  • C The staircase does not run down this cell's side; two cells lie between them.
Q4fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

13Al14Si15P16S17Cl18Ar29Cu30Zn31Ga32Ge33As34Se35Br36Kr47Ag48Cd49In50Sn51Sb52Te53I54Xe79Au80Hg81Tl82Pb83Bi84Po85At86Rn11121314151617183456part of the periodic table: groups 11–18, periods 3–6
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: C — metalloid

Find the ringed cell: atomic number 51, in row 5.
The heavy line runs down its right side and along its top.
An element the staircase runs down the side of is a metalloid.

Feedback per option

  • A A metal sits clear of the staircase, to its left; the staircase runs down this cell's side.
  • B A nonmetal sits clear of the staircase, to its right; the staircase runs down this cell's side.
  • C The staircase runs down the right side of the ringed cell, atomic number 51: a metalloid.
Q5fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

2He5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar30Zn31Ga32Ge33As34Se35Br36Kr121314151617181234part of the periodic table: groups 12–18, periods 1–4
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Find the ringed cell: atomic number 16, in row 3.
The staircase runs two cells to its left, so this cell sits to the right of the staircase.
Elements to the right of the staircase are nonmetals.

Feedback per option

  • A Metals sit to the left of the staircase; this cell sits to its right.
  • B The ringed cell, atomic number 16, sits to the right of the staircase: a nonmetal.
  • C The staircase runs down silicon's side, two cells to the left, not down this cell's side.
Q6fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

19K20Ca21Sc22Ti23V24Cr25Mn26Fe27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr37Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe55Cs56Ba72Hf73Ta74W75Re76Os77Ir78Pt79Au80Hg81Tl82Pb83Bi84Po85At86Rn57–71123456789101112131415161718456part of the periodic table: groups 1–18, periods 4–6
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Find the ringed cell: atomic number 56, second in row 6.
The staircase is far to its right, so the cell sits to the left of the staircase.
Elements to the left of the staircase are metals.

Feedback per option

  • A The ringed cell, atomic number 56, sits far to the left of the staircase: a metal.
  • B Nonmetals sit to the right of the staircase; this cell sits far to its left.
  • C The staircase is many cells away from this cell.
Q7fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

13Al14Si15P16S26Fe27Co28Ni29Cu30Zn31Ga32Ge33As34Se44Ru45Rh46Pd47Ag48Cd49In50Sn51Sb52Te8910111213141516345part of the periodic table: groups 8–16, periods 3–5
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Find the ringed cell: atomic number 45, in row 5.
The staircase runs six cells to its right, so the cell sits to the left of the staircase.
Elements to the left of the staircase are metals.

Feedback per option

  • A The ringed cell, atomic number 45, sits well to the left of the staircase: a metal.
  • B Nonmetals sit to the right of the staircase; this cell sits to its left.
  • C The staircase runs six cells to the right; it does not run down this cell's side.
Q8fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

13Al14Si15P16S17Cl18Ar27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe77Ir78Pt79Au80Hg81Tl82Pb83Bi84Po85At86Rn91011121314151617183456part of the periodic table: groups 9–18, periods 3–6
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: C — metalloid

Find the ringed cell: atomic number 32, in row 4.
The heavy line runs along its top and down its right side.
An element the staircase runs down the side of is a metalloid.

Feedback per option

  • A A metal sits clear of the staircase; the staircase runs down this cell's right side.
  • B A nonmetal sits to the right of the staircase; this cell sits on the line itself.
  • C The staircase runs along the top and down the right side of the ringed cell, atomic number 32: a metalloid.
Q9fluency

The heavy zigzag line is the staircase. Which kind of element is the ringed one?

2He5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar29Cu30Zn31Ga32Ge33As34Se35Br36Kr47Ag48Cd49In50Sn51Sb52Te53I54Xe111213141516171812345part of the periodic table: groups 11–18, periods 1–5
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Find the ringed cell: atomic number 36, at the right end of row 4.
The staircase runs to its left, so the cell sits to the right of the staircase.
Elements to the right of the staircase are nonmetals.

Feedback per option

  • A Metals sit to the left of the staircase; this cell sits at the far right.
  • B The ringed cell, atomic number 36, sits to the right of the staircase: a nonmetal.
  • C The staircase is three cells to the left; it does not run down this cell's side.
Q10fluency

The heavy zigzag line is the staircase. Find fluorine in this part of the table. Which kind of element is fluorine?

2Hehelium5Bboron6Ccarbon7Nnitrogen8Ooxygen9Ffluorine10Neneon13Alaluminum14Sisilicon15Pphosphorus16Ssulfur17Clchlorine18Arargon31Gagallium32Gegermanium33Asarsenic34Seselenium35Brbromine36Krkrypton1314151617181234part of the periodic table: groups 13–18, periods 1–4
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: B — nonmetal

Find fluorine: atomic number 9, row 2.
The staircase runs down boron's side, four cells to fluorine's left, so fluorine sits to the right of the staircase.
Elements to the right of the staircase are nonmetals.

Feedback per option

  • A Metals sit to the left of the staircase; fluorine sits to its right.
  • B Fluorine, atomic number 9, sits to the right of the staircase: a nonmetal.
  • C The staircase runs down boron's side, four cells to fluorine's left, not down fluorine's side.
Q11fluency

The heavy zigzag line is the staircase. Find cadmium in this part of the table. Which kind of element is cadmium?

13Alaluminum14Sisilicon15Pphosphorus16Ssulfur29Cucopper30Znzinc31Gagallium32Gegermanium33Asarsenic34Seselenium47Agsilver48Cdcadmium49Inindium50Sntin51Sbantimony52Tetellurium79Augold80Hgmercury81Tlthallium82Pblead83Bibismuth84Popolonium1112131415163456part of the periodic table: groups 11–16, periods 3–6
  1. A metal
  2. B nonmetal
  3. C metalloid
Answer

Key: A — metal

Find cadmium: atomic number 48, row 5.
The staircase runs three cells to its right, so cadmium sits to the left of the staircase.
Elements to the left of the staircase are metals.

Feedback per option

  • A Cadmium, atomic number 48, sits to the left of the staircase: a metal.
  • B Nonmetals sit to the right of the staircase; cadmium sits to its left.
  • C The staircase runs down antimony's side, three cells to cadmium's right, not down cadmium's side.
Q12misconception

The heavy zigzag line is the staircase. Maren says: "Xenon sits in the far-right column, near the edge of the table, so xenon must be a metalloid." Is Maren correct?

2He5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar29Cu30Zn31Ga32Ge33As34Se35Br36Kr47Ag48Cd49In50Sn51Sb52Te53I54Xe79Au80Hg81Tl82Pb83Bi84Po85At86Rn1112131415161718123456part of the periodic table: groups 11–18, periods 1–6
  1. A yes
  2. B no
Answer

Key: B — no

Find xenon: atomic number 54, at the right end of row 5.
The staircase runs two cells to its left, so xenon sits to the right of the staircase.
Elements to the right of the staircase are nonmetals, so Maren is not correct.

Feedback per option

  • A Near the edge is not the metalloid test. Metalloids sit along the staircase; xenon sits to the right of it, so xenon is a nonmetal.
  • B Xenon sits to the right of the staircase, so xenon is a nonmetal. Metalloids sit along the staircase, not at the table's edge.
Your note · lesson 5: The staircase: where each kind sits
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 6 of 7Author: could do without a video198 words · about 1:39

Columns and rows: groups and periods

MAT-054b · The periodic table's arrangement reflects patterns in properties — Explain how the position of an element in the table relates to its properties.

Script
SayScreen
Lithium, sodium and potassium sit one above another in the first column of the periodic table.[the table; the three cells ringed]
All three are soft metals a knife can cut.[a knife cuts a gray lump]
And all three fizz in water.[a chip fizzes in a beaker]
Helium, neon and argon sit one above another in the last column: three gases that join with nothing.[the last column's three cells ringed; three gas balloons]
Is it a coincidence that column-mates behave alike?[question mark]
No, it is no coincidence.[the two columns glow]
A column of the table is called a group, numbered 1 to 18 across the top.[chip: GROUP; the numbers 1 to 18 glow]
A row of the table is called a period, numbered 1 to 7 down the side.[chip: PERIOD; the numbers 1 to 7 glow]
Lithium, sodium and potassium are group 1; helium, neon and argon are group 18.[group 1 and group 18 columns highlighted]
The makers stacked look-alikes in one column, so elements in the same group share properties.[chip: SAME GROUP, SHARED PROPERTIES]
Now consider period 3: sodium, silicon and chlorine are a metal, a metalloid and a nonmetal.[period 3 highlighted; the three kinds labeled]
A period runs through all three kinds, so a row does not predict what an element is like.[chip: SAME PERIOD, DIFFERENT KINDS]
So, a column of the table is called a group, and a row is called a period.[the rule slide: the numbered table; chips GROUP, PERIOD; nothing else printed]
Elements in the same group share properties.[group 1 glows top to bottom]
So the two columns are groups, and their shared properties are no coincidence.[the two columns ringed]
Okay, now your turn.[closing screen: bullets — • A column of the table is a group • A row of the table is a period • Elements in the same group share properties]

“Okay, now your turn.” — the attached question

video

What is a column of the periodic table called?

  1. A a group
  2. B a period
  3. C a staircase
Answer

Key: A — a group

A column of the table is called a group.
A row is called a period.

Feedback per option

  • A A column is called a group, numbered 1 to 18 across the top.
  • B A period is a row, numbered 1 to 7 down the side.
  • C The staircase is the zigzag line between metals and nonmetals.

Quiz after the video — the mastery check, 11 items

Q1recall

In what order do the boxes of the periodic table run?

  1. A in order of atomic number
  2. B in alphabetical order of name
  3. C in order of how common each element is
Answer

Key: A — in order of atomic number

Each box carries an atomic number, the number of protons.
The boxes run 1, 2, 3 and on to 118.
So the order runs by atomic number.

Feedback per option

  • A The boxes run 1, 2, 3 and on to 118: in order of atomic number.
  • B The order is not alphabetical; the boxes run by atomic number.
  • C How common an element is plays no part; the boxes run by atomic number.
Q2term

A column of the periodic table is called a…

Typed answer

Answer

Accepted: group · a group

The table's columns are numbered 1 to 18 across the top.
A column is called a group.
Q3term

A row of the periodic table is called a…

Typed answer

Answer

Accepted: period · a period

The table's rows are numbered 1 to 7 down the side.
A row is called a period.
Q4what

The numbers across the top of this part of the table are the group numbers; the numbers down the side are the period numbers. In which group is the ringed element?

11Na12Mg19K20Ca21Sc22Ti23V24Cr25Mn26Fe37Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru12345678345part of the periodic table: groups 1–8, periods 3–5

Typed answer

Answer

Accepted: 2 · group 2 · two

Find the ringed cell: atomic number 38, in the second column.
Read the number above that column: 2.
So the ringed element is in group 2.
Q5what

The numbers across the top of this part of the table are the group numbers; the numbers down the side are the period numbers. In which group is the ringed element?

5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe77Ir78Pt79Au80Hg81Tl82Pb83Bi84Po85At86Rn910111213141516171823456part of the periodic table: groups 9–18, periods 2–6

Typed answer

Answer

Accepted: 17 · group 17 · seventeen

Find the ringed cell: atomic number 53.
Read the number above its column: 17.
So the ringed element is in group 17.
Q6what

The numbers across the top of this part of the table are the group numbers; the numbers down the side are the period numbers. In which period is the ringed element?

19K20Ca21Sc22Ti23V24Cr25Mn26Fe27Co37Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru45Rh55Cs56Ba72Hf73Ta74W75Re76Os77Ir87Fr88Ra104Rf105Db106Sg107Bh108Hs109Mt57–7189–1031234567894567part of the periodic table: groups 1–9, periods 4–7

Typed answer

Answer

Accepted: 6 · period 6 · six

Find the ringed cell: atomic number 74.
Read the number at the side of its row: 6.
So the ringed element is in period 6.
Q7what

The numbers across the top of this part of the table are the group numbers; the numbers down the side are the period numbers. In which period is the ringed element?

2He5B6C7N8O9F10Ne13Al14Si15P16S17Cl18Ar28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr1011121314151617181234part of the periodic table: groups 10–18, periods 1–4

Typed answer

Answer

Accepted: 2 · period 2 · two

Find the ringed cell: atomic number 7.
Read the number at the side of its row: 2.
So the ringed element is in period 2.
Q8why

Fluorine, chlorine and bromine sit one under another in group 17. All three join easily with iron. Explain why all three behave alike.

Starter: The table was built by…

Answer

Model answer · ['the table was built by stacking look-alikes in one column', 'a column is a group, and the three sit in the same group', 'so elements in the same group share properties'] points

The table was built by stacking elements that behave alike in the same column.
A column is a group.
Fluorine, chlorine and bromine sit in the same group, group 17.
So the three share properties, and all three join with iron the same way.
Q9misconception

Ayo says: "Elements in the same row share properties, just as elements in the same column do." Is Ayo correct?

  1. A yes
  2. B no
Answer

Key: B — no

The table stacks look-alikes in a column, so a group shares properties.
A period runs through all three kinds, from metals on the left to nonmetals on the right.
Sodium, silicon and chlorine share period 3 and are three different kinds, so a row does not predict what an element is like, and Ayo is not correct.

Feedback per option

  • A Rows do not work like columns. Sodium, silicon and chlorine share a row and are a metal, a metalloid and a nonmetal.
  • B Only a group shares properties. A row runs through all three kinds: sodium, silicon and chlorine share a row and differ.
Q10transfer

The numbers across the top of this part of the table are the group numbers; the numbers down the side are the period numbers. Three cells are ringed: calcium (20), strontium (38) and scandium (21). Which element behaves more like calcium?

3Li4Be11Na12Mg19K20Ca21Sc22Ti23V24Cr25Mn26Fe37Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru123456782345part of the periodic table: groups 1–8, periods 2–5
  1. A strontium
  2. B scandium
Answer

Key: A — strontium

Calcium and strontium sit in the same column, group 2.
Elements in the same group share properties.
Scandium sits beside calcium in the same period, and a row does not predict what an element is like, so strontium behaves more like calcium.

Feedback per option

  • A Calcium and strontium share group 2, and elements in the same group share properties.
  • B Scandium shares only calcium's row, and a row does not predict what an element is like; strontium shares calcium's group.
Q11misconception

Nuria says: "Rubidium sits right under potassium in group 1, so rubidium should behave like potassium." Is Nuria correct?

  1. A yes
  2. B no
Answer

Key: A — yes

Rubidium and potassium sit in the same column, group 1.
The table stacks elements that behave alike in one column, so elements in the same group share properties.
So rubidium behaves like potassium, and Nuria is correct.

Feedback per option

  • A Rubidium and potassium share a group, and elements in the same group share properties: both are soft metals that fizz in water.
  • B Sitting under potassium is exactly the reason. Elements in the same group share properties, so rubidium behaves like potassium.
Your note · lesson 6: Columns and rows: groups and periods
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Lesson 7 of 7Author: definitely a video193 words · about 1:36

Predict a property from the group

MAT-055 · Elements in the same group have similar properties — Predict a property of an unknown element based on the properties of others in the same group.

Script
SayScreen
Francium sits at the bottom of group 1.[the table; francium's cell ringed]
Nobody has ever seen a lump of francium: only a few atoms have ever been gathered.[an empty dish; label: a few atoms only]
Yet chemists say with confidence that francium is a soft metal that reacts with water.[a card: soft metal, reacts with water]
How can they know that about a sample nobody has held?[question mark]
They read francium's group, because elements in the same group share properties.[group 1 lights up top to bottom]
Its group-mates are lithium, sodium, potassium, rubidium and cesium.[the column pulled out; the five names]
Each is a solid that conducts electricity and reacts with water.[the property table fills row by row: solid, yes, yes]
Francium's row is blank, so they copy its group-mates' answers across.[the blank row fills in from the rows above]
Francium sits far to the left of the staircase, so francium is a metal.[the staircase drawn; francium far left; label METAL]
Now consider radon, at the bottom of group 18.[group 18 pulled out; radon ringed]
Its five group-mates are gases that do not react with water, so radon should be one too.[the group 18 table fills; radon's row copies down]
Read the group, not the row. Iodine's row-mates silver and tin conduct electricity.[iodine with silver and tin ringed]
But its group-mates chlorine and bromine do not, and neither does iodine.[iodine with chlorine and bromine ringed]
So, to predict what an element is like, read its group and copy its group-mates' properties across.[the rule slide: the filled group 1 table; nothing else printed]
So francium's group-mates are soft metals that react with water, and francium is too.[francium's filled row]
Okay, now your turn.[closing screen: one line — "To predict what an element is like, read its group and copy its group-mates' properties across."]

“Okay, now your turn.” — the attached question

video

A chemist predicts what francium is like by copying properties from other elements. Which elements does she copy from?

  1. A the elements beside it in period 7
  2. B the elements above it in group 1
  3. C the elements along the staircase
Answer

Key: B — the elements above it in group 1

Elements in the same group share properties.
Francium's group-mates are the elements above it in group 1.
So she copies their answers into francium's row.

Feedback per option

  • A Row-mates do not share properties; she copies from the group.
  • B She reads francium's group-mates, lithium to cesium, and copies their answers across.
  • C The staircase gives the kind, not the row of properties; she copies from the group.

Quiz after the video — the mastery check, 12 items

Q1recall

What is a column of the periodic table called?

  1. A a group
  2. B a period
  3. C a staircase
Answer

Key: A — a group

The table's columns are numbered 1 to 18 across the top.
A column is called a group.

Feedback per option

  • A A column is called a group, numbered 1 to 18 across the top.
  • B A period is a row, numbered 1 to 7 down the side.
  • C The staircase is the zigzag line between the metals and the nonmetals, not a column.
Q2recall

An element's box sits far to the left of the staircase. Which kind of element is it?

  1. A a nonmetal
  2. B a metalloid
  3. C a metal
Answer

Key: C — a metal

Read the position against the staircase.
Elements to the left of the staircase are metals.
So the element is a metal.

Feedback per option

  • A Nonmetals sit to the right of the staircase.
  • B Metalloids sit along the staircase, where the line runs down their side.
  • C Elements to the left of the staircase are metals.
Q3scaffold

Strontium's cell is ringed. Read the number above its column: in which group is strontium?

3Li4Be11Na12Mg19K20Ca21Sc22Ti23V24Cr25Mn26Fe27Co37Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru45Rh55Cs56Ba72Hf73Ta74W75Re76Os77Ir57–7112345678923456part of the periodic table: groups 1–9, periods 2–6

Typed answer

Answer

Accepted: 2 · group 2 · two

Find the ringed cell: atomic number 38, second column.
The number above that column is 2.
So strontium is in group 2.
Q4scaffold

Magnesium and calcium are strontium's group-mates. Read the table: what are they at room temperature?

elementsolid or gas?conducts electricity?magnesiumsolidyescalciumsolidyesstrontium??
  1. A solids
  2. B gases
Answer

Key: A — solids

Read the table's rows for magnesium and calcium.
Each reads solid.
So strontium's group-mates are solids at room temperature.

Feedback per option

  • A Both rows read solid.
  • B Both rows read solid, not gas.
Q5scaffold

Read the table: strontium's group-mates both conduct electricity. Predict: does strontium conduct electricity?

elementsolid or gas?conducts electricity?magnesiumsolidyescalciumsolidyesstrontium??
  1. A yes
  2. B no
Answer

Key: A — yes

Elements in the same group share properties.
Strontium's group-mates magnesium and calcium conduct electricity.
So strontium should conduct electricity too.

Feedback per option

  • A Elements in the same group share properties, so strontium conducts electricity like magnesium and calcium.
  • B Strontium shares its group-mates' properties, and both group-mates conduct electricity.
Q6bare

The table gives two of rubidium's group-mates. Predict: does rubidium react with water?

elementsolid or gas?conducts electricity?reacts with water?sodiumsolidyesyespotassiumsolidyesyesrubidium???
  1. A yes
  2. B no
Answer

Key: A — yes

Read the group-mates' rows: sodium and potassium both react with water.
Elements in the same group share properties.
So rubidium should react with water.

Feedback per option

  • A Sodium and potassium react with water, and elements in the same group share properties.
  • B Both group-mates react with water, so rubidium should too.
Q7bare

The table gives two of xenon's group-mates. Predict: what is xenon at room temperature?

elementsolid or gas?conducts electricity?reacts with water?neongasnonoargongasnonoxenon???
  1. A a solid
  2. B a gas
Answer

Key: B — a gas

Read the group-mates' rows: neon and argon are both gases.
Elements in the same group share properties.
So xenon should be a gas.

Feedback per option

  • A Both group-mates are gases, so xenon should be a gas.
  • B Neon and argon are gases, and elements in the same group share properties.
Q8bare

The table gives two of selenium's group-mates. Predict: does selenium conduct electricity?

elementconducts electricity?oxygennosulfurnoselenium?
  1. A yes
  2. B no
Answer

Key: B — no

Read the group-mates' rows: oxygen and sulfur do not conduct electricity.
Elements in the same group share properties.
So selenium should not conduct electricity.

Feedback per option

  • A Both group-mates fail to conduct, so selenium should fail too.
  • B Oxygen and sulfur do not conduct electricity, and elements in the same group share properties.
Q9bare

The table gives two of radium's group-mates. Predict: what is radium at room temperature?

elementsolid or gas?conducts electricity?calciumsolidyesbariumsolidyesradium??
  1. A a solid
  2. B a gas
Answer

Key: A — a solid

Read the group-mates' rows: calcium and barium are both solids.
Elements in the same group share properties.
So radium should be a solid.

Feedback per option

  • A Calcium and barium are solids, and elements in the same group share properties.
  • B Both group-mates are solids, so radium should be a solid.
Q10bare

The table gives two of gold's group-mates. Predict: does gold react with water?

elementconducts electricity?reacts with water?copperyesnosilveryesnogold??
  1. A yes
  2. B no
Answer

Key: B — no

Read the group-mates' rows: copper and silver do not react with water.
Elements in the same group share properties.
So gold should not react with water.

Feedback per option

  • A Copper and silver do not react with water, so gold should not either.
  • B Copper and silver do not react with water, and elements in the same group share properties.
Q11bare

The table gives two of radon's group-mates. Predict: does radon react with water?

elementsolid or gas?reacts with water?kryptongasnoxenongasnoradon??
  1. A yes
  2. B no
Answer

Key: B — no

Read the group-mates' rows: krypton and xenon do not react with water.
Elements in the same group share properties.
So radon should not react with water.

Feedback per option

  • A Krypton and xenon do not react with water, so radon should not either.
  • B Krypton and xenon do not react with water, and elements in the same group share properties.
Q12misconception

Krypton (36), copper (29) and zinc (30) are ringed. Teo says: "Copper and zinc conduct electricity well, and krypton sits in their row, so krypton conducts well too." Is Teo correct?

13Al14Si15P16S17Cl18Ar27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe9101112131415161718345part of the periodic table: groups 9–18, periods 3–5
  1. A yes
  2. B no
Answer

Key: B — no

A period runs through all three kinds, so a row does not predict what an element is like.
Elements in the same group share properties.
Krypton's group-mates argon and neon do not conduct electricity, so krypton does not, and Teo is not correct.

Feedback per option

  • A A row does not predict what an element is like. Krypton's group-mates argon and neon do not conduct, so krypton does not.
  • B Krypton's group-mates argon and neon do not conduct electricity, so krypton does not. Only a group predicts properties, not a row.
Your note · lesson 7: Predict a property from the group
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Summary video · everything taught, in order, just before the PP100253 words · about 2:06

Summary: The periodic table

Script, part 1 (101 words)
SayScreen
Here is everything we found out about the periodic table.[a still: the whole table]
Every element has a chemical symbol of one or two letters: the first a capital, the second small.[Co, with the C ringed]
Count the capital letters, and you count the elements.[Co, one ring; CO, two rings]
The periodic table is a chart of every known element, one box per element.[the whole table]
The boxes run in order of atomic number, and the atomic number is the number of protons.[the path along the rows; carbon's 6 glows]
To look an element up, find its name on the periodic table, read the symbol in the middle of its box, and read the atomic number at the top.[calcium's box: Ca, 20]
Okay, now your turn.[closing screen: bullets — • Count the capital letters, and you count the elements • The periodic table: every known element, one box each, in order of atomic number • Atomic number = number of protons • Find the name, read the symbol, read the atomic number]

“Okay, now your turn.” — the check question between the parts

video

The symbol Hg has one capital letter. How many elements does Hg name?

  1. A one element
  2. B two elements
  3. C three elements
Answer

Key: A — one element

Count the capital letters, and you count the elements.
Hg has one capital letter, so Hg names one element.

Feedback per option

  • A One capital letter, so one element: mercury.
  • B Two elements would need two capital letters; Hg has one.
  • C Three elements would need three capital letters; Hg has one.
Script, part 2 (152 words)
SayScreen
Here is everything we found out about the kinds of element and where they sit.[a still: the shaded table]
A metal is shiny, conducts electricity, and bends without breaking.[chip: METAL]
A nonmetal is dull, does not conduct electricity, and crumbles or is a gas.[chip: NONMETAL]
And a metalloid looks shiny but shatters, and conducts electricity only a little.[chip: METALLOID]
Metals sit to the left of the staircase, nonmetals to the right, and metalloids along it.[the shaded table; the staircase glows]
There are two exceptions: hydrogen, at the top left, is a nonmetal, and aluminum touches the staircase but is a metal.[H and Al marked]
A column of the table is called a group, and a row is called a period.[the numbers 1 to 18 and 1 to 7 glow]
Elements in the same group share properties.[group 1 lights up]
But a row runs through all three kinds, so a row does not predict what an element is like.[period 3 lights up]
So, to predict what an element is like, read its group and copy its group-mates' properties across.[group 1 pulled out; the property table]
Okay, now your turn.[closing screen: bullets — • Metals left of the staircase, nonmetals right, metalloids along it • A column is a group; a row is a period • Elements in the same group share properties • To predict an element, read its group]

“Okay, now your turn.” — the two questions after part 2

video

Which kind of element is dull, does not conduct electricity, and crumbles or is a gas?

  1. A a metal
  2. B a metalloid
  3. C a nonmetal
Answer

Key: C — a nonmetal

A nonmetal is dull, does not conduct electricity, and crumbles or is a gas.

Feedback per option

  • A A metal is shiny, conducts electricity, and bends without breaking.
  • B A metalloid looks shiny but shatters, and conducts electricity only a little.
  • C A nonmetal is dull, does not conduct electricity, and crumbles or is a gas.
video

Nobody has a sample of radon to test, only its box at the bottom of group 18. Which fact lets a chemist predict what radon is like?

  1. A Elements in the same group share properties.
  2. B Elements in the same period share properties.
  3. C Elements with nearby atomic numbers share properties.
Answer

Key: A — Elements in the same group share properties.

Elements in the same group share properties.
So the chemist reads the elements above radon in group 18 and copies their properties across.

Feedback per option

  • A Elements in the same group share properties, so the chemist reads radon's group-mates above it.
  • B A period runs through metals, metalloids and nonmetals, so a row does not predict what an element is like.
  • C Neighbors by atomic number sit in one row, and a row runs through all three kinds.
Your note · the summary video
What to judge

Is this content better than the current alternative students have (PhysicsGraph / Edmentum)?

8/10 on:

  • Clear and concise language
  • Physics accuracy (read as chemistry accuracy here; his line as pasted for HS Physics)
  • No "clangers" (content that causes a problematic misconception)
  • Appropriate questions
  • Initial testing
  • Expansion into harder questions (no exam)
  • The tasks should use similar language to that of the lesson

Gut check: better than the alternative? Would a student benefit? Full criteria

Applied without asking

Rulings you have already given; in force on every card above, not re-asked.

The topic’s fixed wording (the lexicon the scripts repeat)
  • A substance made of only one kind of atom is called an element.
  • The number of protons decides which element an atom is.
  • Every element has a chemical symbol of one or two letters: the first a capital, the second small.
  • Count the capital letters, and you count the elements.
  • The periodic table is a chart of every known element, one box per element.
  • The boxes run in order of atomic number, and the atomic number is the number of protons.
  • A metal is shiny, conducts electricity, and bends without breaking.
  • A nonmetal is dull, does not conduct electricity, and crumbles or is a gas.
  • A metalloid looks shiny but shatters, and conducts electricity only a little.
  • Metals sit to the left of the staircase, nonmetals to the right, and metalloids along it.
  • A column of the table is called a group, and a row is called a period.
  • Elements in the same group share properties.
  • To predict what an element is like, read its group and copy its group-mates' properties across.

Scripts, questions and quizzes are read from the course content as it stands today; the student site for this topic is here.