0.5 mole of triatomic gas contains ____________________atoms.

Answer

To find the number of atoms in 0.5 moles of a triatomic gas, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Moles**:
- One mole of any substance contains Avogadro's number of entities (atoms, molecules, etc.), which is approximately \(6.02 \times 10^{23}\).

2. **Identify the Type of Gas**:
- The gas in question is a triatomic gas, meaning each molecule of the gas contains 3 atoms.

3. **Calculate the Number of Atoms in One Mole**:
- Since one mole of a triatomic gas contains 3 atoms per molecule, the total number of atoms in one mole is:
\[ 3 \times 6.02 \times 10^{23} \text{ atoms} = 18.06 \times 10^{23} \text{ atoms} \]

4. **Calculate the Number of Atoms in 0.5 Moles**:
- To find the number of atoms in 0.5 moles, we multiply the number of atoms in one mole by 0.5:
\[ \text{Number of atoms in 0.5 moles} = 18.06 \times 10^{23} \times 0.5 \]
- Performing the multiplication:
\[ = 9.03 \times 10^{23} \text{ atoms} \]

5. **Final Result**:
- Therefore, 0.5 moles of triatomic gas contains approximately \(9.03 \times 10^{23}\) atoms.

### Summary:
0.5 mole of triatomic gas contains approximately \(9.03 \times 10^{23}\) atoms.

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