How do you balance these equations
2nan3(s)-> 2na(s)+3n2(g)

The equation is already balanced in the question, but to reach this we must first assume that all chemicals are in a 1:1:1 molar ratio:
NaN3(s) --> Na(s) + N2(g)
Then we count the number of each atom on each side of the reaction:
Atom                     Left hand side                    Right hand side
  Na                                 1                                           1
   N                                  3                                           2
Clearly this is not balanced in terms of N, so to balance this we need to make it so the number of N atoms is the lowest common multiple of 2 and 3, which is 6. Therefore, we use 2 moles of NaN3 and 3 moles of N2 to get 6 N atoms on each side:
2NaN3(s) --> Na(s) + 3N2(g)
Counting atoms:
Atom                     Left hand side                    Right hand side
  Na                                 2                                           2
   N                                  6                                           6
Therefore this balances for all atoms and is the correct balanced equation.
Hope this helps!

Ireally don’t know this

Answer ozone (o3) is made of three atoms of oxygen, it is a molecule;