Writing chemical formulae teaching resources - the science teacher - Free Printable

Let's complete the table by filling in the missing information for each compound. We'll go row by row and determine:

1. Formula – if not given
2. Name – if not given
3. You have seen this substance before... – description or use
4. Element names – what elements are present
5. Number of atoms – how many atoms of each element

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Row 1: CH₄

- Already filled: methane, gas stoves, carbon & hydrogen, 1 C + 4 H ✔

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Row 2: H₂S

- Name: hydrogen sulfide ✔
- Use: rotten egg smell – flatulence ✔
- Elements: Hydrogen and sulfur
- Atoms: 2 x H, 1 x S

✔ Updated:
- Element names: Hydrogen and sulfur
- Number of atoms: 2 x H, 1 x S

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Row 3: O₂

- Formula: O₂
- Name: oxygen
- Use: Breathing (in air), combustion
- Elements: Oxygen
- Atoms: 2 x O

✔ Fill in:
- Name: oxygen
- You have seen: In the air we breathe
- Element names: Oxygen
- Number of atoms: 2 x O

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Row 4: ?

- Given: "Fire extinguishers", 1 x C, 2 x O
- This is carbon dioxide: CO₂
- Name: carbon dioxide
- Elements: Carbon and oxygen
- Atoms: 1 x C, 2 x O ✔

✔ Fill in:
- Formula: CO₂
- Name: carbon dioxide
- Element names: Carbon and oxygen
- Number of atoms: 1 x C, 2 x O

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Row 5: CH₃COOH

- Formula: CH₃COOH → also written as C₂H₄O₂
- Name: acetic acid
- Use: "Putting on chips" → vinegar on chips
- Elements: Carbon, hydrogen, oxygen
- Atoms: 2 x C, 4 x H, 2 x O

✔ Fill in:
- Name: acetic acid
- Element names: Carbon, hydrogen, oxygen
- Number of atoms: 2 x C, 4 x H, 2 x O

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Row 6: C₁₂H₂₂O₁₁

- Name: sucrose ✔
- Use: Table sugar ✔
- Elements: Carbon, hydrogen, oxygen
- Atoms: 12 x C, 22 x H, 11 x O

✔ Fill in:
- Element names: Carbon, hydrogen, oxygen
- Number of atoms: 12 x C, 22 x H, 11 x O

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Row 7: ?

- Use: "Used to bleach hair"
- Atoms: 2 x H, 2 x O → likely hydrogen peroxide, H₂O₂
- Formula: H₂O₂
- Name: hydrogen peroxide
- Elements: Hydrogen and oxygen

✔ Fill in:
- Formula: H₂O₂
- Name: hydrogen peroxide
- Element names: Hydrogen and oxygen
- Number of atoms: 2 x H, 2 x O

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Row 8: C₈H₁₀N₄O₂

- Name: caffeine ✔
- Use: In coffee, tea, energy drinks
- Elements: Carbon, hydrogen, nitrogen, oxygen
- Atoms: 8 x C, 10 x H, 4 x N, 2 x O

✔ Fill in:
- Element names: Carbon, hydrogen, nitrogen, oxygen
- Number of atoms: 8 x C, 10 x H, 4 x N, 2 x O

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Row 9: C₈H₉NO₂

- Name: paracetamol ✔
- Use: Painkiller/fever reducer (e.g., Tylenol)
- Elements: Carbon, hydrogen, nitrogen, oxygen
- Atoms: 8 x C, 9 x H, 1 x N, 2 x O

✔ Fill in:
- Element names: Carbon, hydrogen, nitrogen, oxygen
- Number of atoms: 8 x C, 9 x H, 1 x N, 2 x O

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Row 10: copper

- Name: copper ✔
- Formula: Cu (elemental form)
- Use: Wires, plumbing, coins
- Elements: Copper (only one element)
- Atoms: 1 x Cu (as a single atom in elemental form)

✔ Fill in:
- Formula: Cu
- You have seen: Electrical wires, pennies, pipes
- Element names: Copper
- Number of atoms: 1 x Cu

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✔ Final Completed Table:

| # | Formula | Name | You have seen this substance before... | Element names | Number of atoms |
|---|-------------|------------------|-----------------------------------------------|----------------------------------|-------------------------------|
| 1 | CH₄ | methane | Gas stoves for cooking | Carbon and hydrogen | 1 x C, 4 x H |
| 2 | H₂S | hydrogen sulfide | Rotten egg smell – flatulence | Hydrogen and sulfur | 2 x H, 1 x S |
| 3 | O₂ | oxygen | In the air we breathe | Oxygen | 2 x O |
| 4 | CO₂ | carbon dioxide | Fire extinguishers | Carbon and oxygen | 1 x C, 2 x O |
| 5 | CH₃COOH | acetic acid | Putting on chips (vinegar) | Carbon, hydrogen, oxygen | 2 x C, 4 x H, 2 x O |
| 6 | C₁₂H₂₂O₁₁ | sucrose | Table sugar | Carbon, hydrogen, oxygen | 12 x C, 22 x H, 11 x O |
| 7 | H₂O₂ | hydrogen peroxide| Used to bleach hair | Hydrogen and oxygen | 2 x H, 2 x O |
| 8 | C₈H₁₀N₄O₂ | caffeine | In coffee, energy drinks | Carbon, hydrogen, nitrogen, oxygen | 8 x C, 10 x H, 4 x N, 2 x O |
| 9 | C₈H₉NO₂ | paracetamol | Painkiller (e.g., Tylenol) | Carbon, hydrogen, nitrogen, oxygen | 8 x C, 9 x H, 1 x N, 2 x O |
|10 | Cu | copper | Electrical wires, coins, pipes | Copper | 1 x Cu |

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✔ Summary:

We used chemical knowledge to identify:
- Formulas from descriptions (like fire extinguishers → CO₂)
- Names from formulas (like CH₃COOH → acetic acid)
- Element names from symbols (C, H, O, N, S, Cu)
- Counted atoms in each molecule.

This exercise helps connect real-world substances with their chemical identities!