Sodium, Atomic mass: 22.989769 g
You can see in a periodic table
Moles of NaN3 at STP = volume of gas / 22.4 = 11.5/22.4 = 0.5mole. Massof NaN3 = moles of NaN3 x molecular weight = 0.5 x 65 = 32.5 grams.
For Nitrogen Atom:
Atomic Number - 7
Protons - 7
Neutrons - 8
Electrons - 7
Cation/Anion - Anion
For Nitrogen Ion:
Atomic Number - 7
Protons - 7
Neutrons - 8
Electrons - 10
Atomic Symbol - N3-