Which among the following contains 12 atoms of oxygen?

Options

A. 6 molecules of calcium oxide
B. 6 moelcules of water
C. 3 molecules of sodium bicarbonate
D. 4 molecules of calcium carbonate

Explanation

To determine which option contains 12 atoms of oxygen, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the options given**: We have four options to evaluate:
- Option 1: 6 molecules of Calcium Oxide (CaO)
- Option 2: 6 molecules of Water (H₂O)
- Option 3: 3 molecules of Sodium Bicarbonate (NaHCO₃)
- Option 4: 4 molecules of Calcium Carbonate (CaCO₃)

2. **Calculate the number of oxygen atoms in each option**:
- **Option 1: 6 molecules of Calcium Oxide (CaO)**
- Each molecule of CaO contains 1 oxygen atom.
- Therefore, 6 molecules will contain:
\[ 6 \text{ molecules} \times 1 \text{ oxygen atom/molecule} = 6 \text{ oxygen atoms} \]

- **Option 2: 6 molecules of Water (H₂O)**
- Each molecule of H₂O contains 1 oxygen atom.
- Therefore, 6 molecules will contain:
\[ 6 \text{ molecules} \times 1 \text{ oxygen atom/molecule} = 6 \text{ oxygen atoms} \]

- **Option 3: 3 molecules of Sodium Bicarbonate (NaHCO₃)**
- Each molecule of NaHCO₃ contains 3 oxygen atoms.
- Therefore, 3 molecules will contain:
\[ 3 \text{ molecules} \times 3 \text{ oxygen atoms/molecule} = 9 \text{ oxygen atoms} \]

- **Option 4: 4 molecules of Calcium Carbonate (CaCO₃)**
- Each molecule of CaCO₃ contains 3 oxygen atoms.
- Therefore, 4 molecules will contain:
\[ 4 \text{ molecules} \times 3 \text{ oxygen atoms/molecule} = 12 \text{ oxygen atoms} \]

3. **Conclusion**:
- From the calculations, we find that:
- Option 1 has 6 oxygen atoms.
- Option 2 has 6 oxygen atoms.
- Option 3 has 9 oxygen atoms.
- Option 4 has 12 oxygen atoms.
- Therefore, the option that contains 12 atoms of oxygen is **Option 4: 4 molecules of Calcium Carbonate (CaCO₃)**.

### Final Answer:
**Option 4: 4 molecules of Calcium Carbonate (CaCO₃) contains 12 atoms of oxygen.**

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