What are the ways nitrogen enters and leaves the atmosphere?

Nitrogen enters the atmosphere primarily through volcanic eruptions and the release of gases from the Earth's crust. It also comes from biological processes, such as denitrification, where bacteria convert nitrates in soil back into nitrogen gas. Nitrogen leaves the atmosphere mainly through nitrogen fixation, where certain bacteria convert atmospheric nitrogen into ammonia, and through processes like precipitation, where nitrogen compounds are deposited back to the Earth's surface. Additionally, human activities, such as burning fossil fuels and industrial processes, can also influence nitrogen levels in the atmosphere.