Question

What do the following denote ?

1. N
2. 2N
3. N₂
4. 2N₂

Answer 1

1. N refers to an atom of nitrogen.
2. 2N represents two atoms of nitrogen which are not chemically bonded.
3. N₂ refers to a molecule of nitrogen gas. Two atoms of nitrogen chemically bond to give a molecule of nitrogen gas.
4. 2N₂ refers to two molecules of nitrogen gas.