🔬 Part 1: Counting Atoms in Compounds

1. How many atoms of each element are in H₂O?

Hydrogen: _____ atoms

Oxygen: _____ atoms

2. How many atoms of each element are in Ca(OH)₂?

Calcium: _____ atoms

Oxygen: _____ atoms

Hydrogen: _____ atoms

3. What is the total number of atoms in Al₂(SO₄)₃?

17 atoms

20 atoms

14 atoms

23 atoms

4. Count the atoms in 3Mg(NO₃)₂:

Magnesium: _____ atoms

Nitrogen: _____ atoms

Oxygen: _____ atoms

⚖️ Part 2: Chemical Equations

5. In the equation: 2H₂ + O₂ → 2H₂O

How many hydrogen atoms are on the left side? _____

How many oxygen atoms are on the right side? _____

6. For the equation: CaCO₃ → CaO + CO₂

Is this equation balanced?

Yes

No

Explain your answer:

7. Balance this equation by filling in the coefficients:

_____ Al + _____ O₂ → _____ Al₂O₃

🧪 Part 3: Identifying Reactants and Products

8. For the equation: 2Na + Cl₂ → 2NaCl

Reactants: ____________________

Products: ____________________

9. In the following equation: CH₄ + 2O₂ → CO₂ + 2H₂O

Circle the reactants:

CH₄

O₂

CO₂

H₂O

10. For the equation: 2AgNO₃ + CaCl₂ → 2AgCl + Ca(NO₃)₂

How many different reactants are there? _____

How many different products are there? _____

Name one product: ____________________

11. Complete the table for the equation: Fe + S → FeS

Reactants	Products

🔬 Part 4: Challenge Problems

12. Balance the following equation:

_____ C₄H₁₀ + _____ O₂ → _____ CO₂ + _____ H₂O

13. In the balanced equation: 2Fe + 3CuSO₄ → Fe₂(SO₄)₃ + 3Cu

How many total atoms are on each side of the equation?

Left side: _____ atoms

Right side: _____ atoms

14. Write and balance the equation for the reaction between aluminium and hydrochloric acid (HCl) to produce aluminium chloride (AlCl₃) and hydrogen gas (H₂):

15. For the equation: 2KClO₃ → 2KCl + 3O₂

Count the atoms of each element in the reactants:

Potassium: _____ atoms

Chlorine: _____ atoms

Oxygen: _____ atoms

Is this equation balanced? _____

Atoms and Chemical Equations

Atoms and Chemical Equations

🔬 Part 1: Counting Atoms in Compounds

⚖️ Part 2: Chemical Equations

🧪 Part 3: Identifying Reactants and Products

🔬 Part 4: Challenge Problems

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