Question

Which of the following inert gas is found most abundant in the atmosphere?
A) $He$
B) $Ne$
C) $Ar$
D) $Kr$
E) $Xe$

Answer 1

As we know that inert gases are chemically unreactive and they generally form very few compound and some of them are of radioactive origin, some are rarest elements of the group and all of these inert gases occur in atmosphere and the abundance in dry air is approximately $1\%$.

Complete step by step solution:
As we know that inert gases are mostly those which form a very few compounds which is why they are termed as noble gases and are chemically unreactive. The general electronic configuration is $n{s^2}n{p^6}$.
We also know that all the noble gases except radon occurs in the atmosphere. This abundance in dry air is approximately $1\%$ by volume of which Argon is the main constituent. Helium and Neon are sometimes found in minerals of radioactive origin like pitchblende, monazite and cleveite.
Among these gases Xenon and Radon are the rarest elements of the group and Radon is obtained as a radioactive decay product of $R{a^{226}}$.
Argon being the most commonest noble gas, makes up nearly one percent of earth’s atmosphere. It is the third-lightest of all the six noble gases and helium is the second lightest, Neon being the tenth.
Therefore, we can say that Argon is the most abundant noble gases present in the atmosphere.

Therefore, from the above explanation we can say that the correct answer is (C).

Note: Remember that Argon is a colourless, odourless and tasteless gas. It can be used along with potassium to date the objects which are billions years old. Argon can also be used in welding of alloys and automobiles frames, mufflers and other automotive parts. It is also used for heat treating processes to provide oxygen and nitrogen free settings.

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