Answer:
N₂ (g) + O₂ (g) ---> 2 NO (g)
Step-by-step explanation:
Nitrogen and oxygen are both diatomic elements. This means that, on their own, there must always be two atoms present (denoted by the subscript 2). In nitrogen monoxide, there is one nitrogen and one oxygen atom present.
The unbalanced equation is:
N₂ (g) + O₂ (g) ---> NO (g)
As you can see, on the reactant side, there are two nitrogen and two oxygen atoms. On the product side, there is only one of each element. Therefore, this equation can be balanced by placing a coefficient of 2 in front of nitrogen monoxide.
The balanced equation is:
N₂ (g) + O₂ (g) ---> 2 NO (g)