Calculate the mass of 2.5 g atom of oxygen.

Explanation

To calculate the mass of 2.5 gram atoms of oxygen, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Gram Atom**:
- A gram atom (or mole) is the amount of a substance that contains as many entities (atoms, molecules, etc.) as there are in 12 grams of carbon-12.

2. **Identify the Molar Mass of Oxygen**:
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