Question

What is the source of oxygen gas in the air?

Answer 1

Hint: Plants convert light energy to chemical energy via the process of photosynthesis. The products released by plants as a result of photosynthesis helps in the survival of all living organisms.

Complete answer:
-The word photosynthesis is derived from the Greek word ‘phos’ meaning “light’’ and ‘synthesis’ meaning “putting together”.

-The chemical energy formed by the plants are stored in the form of carbohydrate molecules, such as sugars which are synthesized from carbon dioxide and water.
-The general reaction of the photosynthesis is given as-
$6C{{O}_{2}}+6{{H}_{2}}O\xrightarrow[Chlorophyll]{Sunlight}{{C}_{6}}{{H}_{12}}{{O}_{6}}+6{{O}_{2}}$

-Most of the plants, algae, and bacteria perform photosynthesis and such organisms are called photoautotrophs.
-The process of photosynthesis is largely responsible for the production and maintenance of oxygen content in the earth’s atmosphere and thus is a major supplier of energy for life on earth.
-The oceans also provide a major production of oxygen to the air. Oxygen from the oceans comes from the tiny ocean plants called phytoplankton.
-Phytoplankton are the microscopic plants that live near the water surface and drifts with the water currents. They, being a plant, produce oxygen via the process of photosynthesis.
-Scientists believe that the oxygen contributed by phytoplankton is nearly 50-80% of the oxygen in the earth’s atmosphere.
-In chemistry language, photosynthesis is a light-energizing oxidation-reduction process. The energy-driven from the sun brings the oxidation of water producing oxygen gas, hydrogen gas, and electrons. The removed electrons and hydrogen ions are transferred to carbon dioxide which is further used for reducing carbon dioxide to organic products and for the reductions of nitrates and sulfate to amino acids and sulfhydryl groups in amino acids.

Note:
The first oxygen-producing cells discovered were the blue-green algae (cyanobacteria), which appeared about two billion to three billion years ago. John Priestly discovered oxygen gas.