Question

Who discovered oxygen gas
A. Priestley
B. Erlich
C. Chadwick
D. Tansley

Answer 1

Hint: He has discovered carbonated water and different types of gases.

Complete answer:
Oxygen gas was discovered by Joseph Priestley in 1774. The oxygen gas exists as colorless, odorless, and tasteless gas at standard temperature and pressure. The molecular formula of oxygen is $O_2$ that is referred to as dioxygen. Oxygen comprises almost 21% of the total gases in the air and is also essential for respiration because the body utilizes it to 'burn' food molecules.

Additional information:
> The solubility of oxygen is higher in water than nitrogen, and it dissolves in freshwater more readily than seawater.
> The solubility of oxygen in water is a temperature-dependent phenomenon.
> Freshwater comprises about 6.04 milliliters (mL) of oxygen per liter at room temperature and standard atmosphere of air.
> It is the highly abundant chemical element by mass in the Earth's planet.
> During oxygenic photosynthesis, free oxygen is produced by the light-driven splitting of water.
> It is considered as green algae and cyanobacteria in marine environments provide about 70% of the free oxygen produced on Earth.
> Oxygen gas becomes toxic at elevated partial pressures that lead to convulsions and other health problems.
> Oxygen is a nonmetal and has low thermal and electrical conductivity.
> Plants and animals both require oxygen for respiration.
> Oxygen is paramagnetic in nature that weakly attracts a magnet but doesn't retain its permanent magnetism.

So, the correct answer is ‘Priestley’.

Note:
> In hypoxia condition, the body or a part of the body is deprived of adequate oxygen supply at the tissue level.
> Haemoglobin plays an important role in the transportation of oxygen around the body via the blood. Each molecule of haemoglobin binds with four oxygen molecules.