Question

Percentage of \[Ar\] in air is about
(a) 1%
(b) 2%
(c) 3%
(d) 4%

Answer 1

Hint: In the atmosphere, argon gas is considered as the third most abundant gas. In the periodic table, argon gas is represented by the symbol \[Ar\]and has the atomic number 18. Argon gas is obtained by the use of an isotope of potassium-40(\[K - 40\]) but in industry, it is produced by the fractional distillation of liquid air.

Complete Step by Step Solution:
Air is composed of the following gases:
Nitrogen (\[{N_2}\])= 78.09%
Oxygen (\[{O_2}\])=20.95%
Argon (\[Ar\])=0.93%
Carbon dioxide (\[C{O_2}\]) and other gases are present in traces.

Due to the unreactive or inert nature of argon, it has various applications. Argon gas prevents the combustion of graphite in graphite furnaces. Argon gas is also used in a fluorescent lamp. Argon gas is also used to avoid the oxidation of filaments. Because the argon gas is colourless and odourless. Therefore, the prediction of argon gas around us is very difficult.

In the field of medical science, argon gas can be used in the treatment of tumours and in the treatment of eye defects. Argon gas can also be used to produce a bluish-green laser.
From the above discussion, we can conclude that argon gas is an inert gas and due to its inert nature, it has various applications. The above discussion also indicates the percentage of argon in the atmosphere is 0.93% (nearly 1%). Hence, option (a) will be the correct answer.

Note: Argon has three isotopes (argon-36 , argon-30 and argon-40). Unlike xenon, krypton, and radon, argon does not form any compounds with fluorine and oxygen due to its inert nature.