Complete the sentence.
In this chemical reaction, nitric oxide is a ().

 - reactant
 - product
Read the underlined text carefully. Look for information about what happens to nitric oxide in this chemical reaction.
Did you know that lightning helps provide nutrients to plants on Earth? When lightning strikes, the air around it becomes extremely hot. This leads to the formation of nitric oxide from the nitrogen and oxygen gases in the air. Nitric oxide plays an important role in helping plants grow.
The underlined text tells you that nitric oxide forms when nitrogen combines with oxygen. Because nitric oxide is produced by this chemical reaction, nitric oxide is a product.