How are oxygen and nitrogen found in the air?

Oxygen and nitrogen are found in the air as diatomic molecules, meaning that they exist as pairs of atoms. Oxygen is primarily found as O2, while nitrogen is found as N2. The diatomic nature of these gases is crucial for their stability and the roles they play in various biological and chemical processes. This arrangement allows each molecule to achieve full stability as the atoms share electrons.

In the context of atmospheric science and chemistry, the concentration of diatomic oxygen and nitrogen makes up approximately 21% and 78% of the Earth's atmosphere, respectively. This molecular form is also significant because it enables the gases to participate in reactions such as combustion, respiration, and photosynthesis without the complications that arise from other forms, such as solids or aerosols.

Understanding the molecular structure of these gases helps articulate their behavior and reactivity in various contexts, including their roles in respiration for living organisms and their contribution to atmospheric processes.