Molecular nitrogen is the most abundant gas in Earth's atmosphere. Nitrogen atoms are also found in other important atmospheric gases.
Nitric oxide and nitrogen dioxide are two gases whose molecules are made of nitrogen and oxygen atoms. Nitrogen dioxide is a major air pollutant.
Oxygen is an important gas in the air we breathe. About 21% of Earth's atmosphere is oxygen.
Ozone is an unusual type of oxygen molecule. Ozone in the troposphere is harmful, while stratospheric ozone is beneficial.
This comic lets particulate matter, or aerosols, speak for themselves. It turns out that big hazards can come in small packages.
Volatile Organic Compounds (VOCs)
Good air quality is critical for maintaining life on Earth. But what is air quality and why does it change?
Resource Type: Information
Air is a mixture of naturally occurring gases and human-made air pollutants. Learn more about these gases and the role they play in our atmosphere.
Resource Type: Information
When a wildfire was burning dangerously close to Boulder, Colorado, we found evidence of the smoke in the data feed of our air quality exhibit.