* A single nitrogen atom: There's just one atom in a single nitrogen atom.
* A nitrogen molecule (N2): A nitrogen molecule is made of two nitrogen atoms bonded together. So, there are two atoms in a nitrogen molecule.
* A mole of nitrogen (N2): One mole of anything contains Avogadro's number of particles. This is approximately 6.022 x 10^23. Since a nitrogen molecule has two atoms, a mole of nitrogen gas contains 1.2044 x 10^24 atoms.
So, the answer depends on what you're asking about!