The worksheet titled
"Counting Atoms" asks you to count the number of atoms in various chemical formulas and fill in a table with the correct numbers. Let's go through each compound one by one, explain how to count the atoms, and verify the answers provided.
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🔹 Understanding How to Count Atoms
-
Subscripts: The small numbers after an element symbol indicate how many atoms of that element are in one molecule.
- Example: In H₂O, the "2" means 2 hydrogen atoms.
-
Coefficients: Numbers in front of a formula (like 3H₂O) multiply all atoms in that formula.
- Example: 3H₂O means 3 × (2H + 1O) = 6H + 3O.
Let’s analyze each box:
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✔ 1. H₂O
- H: 2
- O: 1
-
Total: 2 + 1 = 3 → ✔️ Correct
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✔ 2. H₂O₂
- H: 2
- O: 2
-
Total: 2 + 2 = 4 → ✔️ Correct
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✔ 3. CH₄
- C: 1
- H: 4
-
Total: 1 + 4 = 5 → ✔️ Correct
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✔ 4. 3H₂O
- Coefficient = 3
- Each H₂O has 2H and 1O
- So: 3 × 2H = 6H, 3 × 1O = 3O
-
Total: 6 + 3 = 9 → ✔️ Correct
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✔ 5. 3NaCl
- Na: 3
- Cl: 3
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Total: 3 + 3 = 6 → ✔️ Correct
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✔ 6. 6CO₂
- CO₂ has 1C and 2O
- Multiply by 6: 6 × 1C = 6C, 6 × 2O = 12O
-
Total: 6 + 12 = 18 → ✔️ Correct
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✔ 7. H₂SO₄
- H: 2
- S: 1
- O: 4
-
Total: 2 + 1 + 4 = 7 → ✔️ Correct
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✔ 8. C₆H₁₂O₆
- C: 6
- H: 12
- O: 6
-
Total: 6 + 12 + 6 = 24 → ✔️ Correct
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✔ 9. 2AgNO₃
- AgNO₃ has:
- Ag: 1
- N: 1
- O: 3
- Multiply by 2: 2Ag, 2N, 6O
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Total: 2 + 2 + 6 = 10 → ✔️ Correct
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🟩 Final Answer Summary: All entries are already correct!
| Formula | Elements | Count | Total |
|-------------|----------|-------|-------|
| H₂O | H=2, O=1 | 3 | ✔️ |
| H₂O₂ | H=2, O=2 | 4 | ✔️ |
| CH₄ | C=1, H=4 | 5 | ✔️ |
| 3H₂O | H=6, O=3 | 9 | ✔️ |
| 3NaCl | Na=3, Cl=3 | 6 | ✔️ |
| 6CO₂ | C=6, O=12 | 18 | ✔️ |
| H₂SO₄ | H=2, S=1, O=4 | 7 | ✔️ |
| C₆H₁₂O₆ | C=6, H=12, O=6 | 24 | ✔️ |
| 2AgNO₃ | Ag=2, N=2, O=6 | 10 | ✔️ |
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✔ Conclusion:
All the values in the table are
correctly filled out. No corrections needed!
This worksheet helps reinforce understanding of:
- Subscripts (e.g., H₂)
- Coefficients (e.g., 3H₂O)
- Total atom counting in molecules
Great job if you completed it — or great teaching if you're reviewing it! 😊
Parent Tip: Review the logic above to help your child master the concept of practice counting atoms worksheet answers.
