Question

The percentage of oxygen in the air is
(a)78%
(b)0.03%
(c)21%
(d)80%

Answer 1

Hint: Nitrogen gas contributes the maximum amount to the atmospheric gases, the rest of the gases occupy a minimal amount of the atmosphere which is less than 1%. The second most abundant gas in the atmosphere is oxygen.

Complete answer:
Oxygen is present in 21% of the atmosphere. Along with air, it holds many tiny dust particles called aerosols. Air carrying a large amount of these particles is termed as air pollution and forms soot in the atmosphere.

Additional Information: -The major source of oxygen in the atmosphere is trees, tiny ocean plants called phytoplankton, and some bacteria.
-Phytoplankton lives under the water where the use of sunlight and carbon dioxide to make food and release oxygen as a by-product.
-Oxygen is present in two forms- oxygen O2 and ozone O3.
-Ozone is the upper layer of the atmosphere which protects us from the harmful radiation of the sun.
-Aloe vera is a plant that releases oxygen at night and that purifies the air also removing toxins like aldehyde and benzene.

So, the correct answer is, ‘ 21%.’

Note: -Half of the oxygen in the atmosphere is coming from the phytoplankton photosynthesis and another half by the photosynthesis on land by the tree.
-Trees like fig, eucalyptus, locust, Chinese elms, catalpa are thought to produce a high amount of oxygen.
-Company Air liquid and integrated energy and chemical company Sasol have officially inaugurated the world’s largest oxygen production plant in South Africa.