1 g-atom of nitrogen represents

Options

A. `6.02xx10^(23) N_(2)` molecules
B. `22*4 L` of `N_(2)` at S.T.P.
C. `11*2 L` of `N_(2)` at S.T.P.
D. 28 g of nitrogen

Explanation

To solve the problem of determining what 1 gram atom of nitrogen represents, we need to understand the concept of gram atoms and how it relates to Avogadro's number and molar volume at standard temperature and pressure (STP).

### Step-by-Step Solution:

1. **Definition of Gram Atom:**
- 1 gram atom of an element is the amount of the element whose mass in grams is numerically equal to its atomic mass.
- For nitrogen (N), the atomic mass is 14 grams per mole.

2. **Avogadro's Number:**
- Avogadro's number (NA) is \(6.02 \times 10^{23}\) atoms/molecules per mole.
- Therefore, 1 gram atom of nitrogen contains \(6.02 \times 10^{23}\) nitrogen atoms.

3. **Molecular Form of Nitrogen:**
- Nitrogen naturally exists as a diatomic molecule (N2).
- Hence, 1 mole of N2 contains \(6.02 \times 10^{23}\) molecules of N2.

4. **Conversion to Molecules of N2:**
- Since 1 gram atom of nitrogen (N) is equivalent to 1 mole of nitrogen atoms, and each N2 molecule contains 2 nitrogen atoms:
\[ \text{Number of } N2 \text{ molecules} = \frac{6.02 \times 10^{23} \text{ atoms}}{2} = 3.01 \times 10^{23} \text{ molecules of N2} \]

5. **Moles of N2:**
- Therefore, 1 gram atom of nitrogen corresponds to 0.5 moles of N2 because:
\[ 1 \text{ mole of N2} = 2 \text{ moles of N} \]
\[ 0.5 \text{ moles of N2} = 1 \text{ mole of N} \]

6. **Volume at STP:**
- At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 liters.
- Therefore, 0.5 moles of N2 will occupy:
\[ \text{Volume} = 0.5 \times 22.4 \text{ liters} = 11.2 \text{ liters} \]

### Conclusion:
1 gram atom of nitrogen represents:
- \(6.02 \times 10^{23}\) nitrogen atoms.
- \(3.01 \times 10^{23}\) molecules of N2.
- 0.5 moles of N2.
- 11.2 liters of N2 gas at STP.

Thus, the correct answer is: **11.2 liters of nitrogen gas at STP**.