Here's how to write the balanced equation for the reaction of hydrogen and nitrogen to produce ammonia:

1. Write the unbalanced equation:

N₂ + H₂ → NH₃

2. Balance the nitrogen atoms:

N₂ + H₂ → 2NH₃

3. Balance the hydrogen atoms:

N₂ + 3H₂ → 2NH₃

The balanced equation is:

N₂ + 3H₂ → 2NH₃

Explanation:

* N₂ represents nitrogen gas, which exists as a diatomic molecule.

* H₂ represents hydrogen gas, also a diatomic molecule.

* NH₃ represents ammonia.

The coefficients (numbers in front of the molecules) ensure that the same number of each type of atom appears on both sides of the equation. This satisfies the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction.