The process in which bacteria convert nitrates into nitrogen gas and releases it to the atmosphere is called denitrification.

Here's a breakdown:

* Nitrates (NO3-) are a form of nitrogen readily available to plants.

* Denitrifying bacteria are a group of microorganisms that use nitrates as an electron acceptor in their respiration process.

* Respiration is the process by which organisms break down organic matter to release energy. In this case, the denitrifying bacteria use nitrates to generate energy.

* Nitrogen gas (N2) is the byproduct of this process and is released into the atmosphere.

The denitrification process is a crucial part of the nitrogen cycle, ensuring that nitrogen is not perpetually locked up in the soil.

Here's a simplified summary:

1. Nitrates (NO3-) are present in the soil.

2. Denitrifying bacteria use the nitrates to generate energy.

3. Nitrogen gas (N2) is released into the atmosphere.

This cycle helps to maintain the balance of nitrogen in the environment.