Which nonmetal in the atmosphere and their combinations are essential to life on eartj?

Oxygen is a nonmetal in the atmosphere that is essential to life on Earth. It makes up about 21% of the atmosphere and is needed for respiration in most living organisms. Nitrogen is another nonmetal in the atmosphere that is also important for life as it is a crucial component of proteins and DNA. Water vapor, a combination of hydrogen and oxygen, is also essential for life on Earth.