1, 2, 1, 2, in that order.
Nitrogen N I think would be the answer
It's because the Law of Conservation of Mass WILL NOT be followed if,
from SO2 and water, sulfuric acid is formed. Making a balanced chemical
reaction is not possible, no matter what you do. To obtain or make sulfuric acid, SO2
still needs to be oxidized further to SO3.
If an atom suffers from a collision, that causes an electron to jump from a lower to higher state, it is called collisional excitation