The correct chemical formula of nitrous oxide is
a.) N2O

b.) NO
c.) NO2

d.) N2O3

The correct answer is a) N₂O.

Explanation:
Nitrous oxide is a chemical compound commonly known as "laughing gas." It consists of two nitrogen atoms and one oxygen atom. The chemical formula for nitrous oxide is N₂O.

Here’s a breakdown of the options:

N₂O (Nitrous oxide): Correct formula of nitrous oxide.

NO (Nitric oxide): This is a different compound known as nitric oxide, which has one nitrogen atom and one oxygen atom. It is not the same as nitrous oxide.

NO₂ (Nitrogen dioxide): This is another nitrogen-oxygen compound, nitrogen dioxide, which contains one nitrogen atom and two oxygen atoms.

N₂O₃ (Dinitrogen trioxide): This is a separate compound called dinitrogen trioxide, which has two nitrogen atoms and three oxygen atoms. It is different from nitrous oxide.

Thus, the correct answer is N₂O (a).