Answer: Approximately [tex]0.48 \times 10^{-2} \ \text{ mole}[/tex]
============================================================
Explanation:
There are roughly 6.02 * 10^23 atoms in one mole of any element. So we have 6.02 * 10^23 atoms in one mole of nitrogen.
We can then do the following conversion:
[tex]\left(2.9 \times 10^{21} \ \text{ atoms of nitrogen} \right)\times \left(\frac{1 \ \text{ mole}}{6.02 \times 10^{23} \ \text{ atoms}}\right)\\\\\frac{2.9 \times 10^{21}}{6.02 \times 10^{23}} \ \text{ mole}\\\\\frac{2.9}{6.02} \times 10^{21-23} \ \text{ mole}\\\\0.48172757 \times 10^{-2} \ \text{ mole}\\\\0.48 \times 10^{-2} \ \text{ mole}\\\\[/tex]
