Question

How is oxygen renewed in the air?

Answer 1

Renewal of oxygen in the air -

• Air contains about 21 percent of oxygen by volume.
• It is required for respiration by all living organisms.
• During respiration, oxygen breaks down food to give energy, and carbon dioxide is released.

$\underset{\mathrm{Glucose}}{{\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6}+\underset{\mathrm{Oxygen}}{6{\mathrm{O}}_2}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{6{\mathrm{CO}}_2}+\underset{\mathrm{Water}\mathrm{vapour}}{6{\mathrm{H}}_2\mathrm{O}}+\mathrm{Energy}$

• Oxygen is also used up in the burning of fuels and the rusting of iron.
• Aquatic animals also take in oxygen dissolved in water.
• The amount of oxygen in the atmosphere remains more or less constant because the carbon dioxide released during respiration and the burning of fuels is utilized by the green plants to produce food by photosynthesis and release oxygen into the air.

$\underset{\mathrm{Carbon}\mathrm{dioxide}}{6{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{6{\mathrm{H}}_2\mathrm{O}}\to \underset{\mathrm{Glucose}}{{\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6}+\underset{\mathrm{Oxygen}}{6{\mathrm{O}}_2}$

• Thus, in nature, oxygen and carbon dioxide are consumed and produced continuously.
• As a result, the oxygen-carbon dioxide balance in the atmosphere is maintained.
• This circulation of oxygen in nature is called the oxygen cycle.

Oxygen cycle