Question

Total number of inert gases among the following is:
${\text{H,He,Ne,F,Ar,Kr,K}}$
A. $1$
B. $2$
C. $3$
D. $4$

Answer 1

The gases or the elements which don’t react with the other elements easily are known as noble or inert gases. These elements do not react with the other elements because their outermost octet is fully filled with electrons and they are stable.

Complete step by step answer:
The gases which do not react to form new compounds are known as inert gases. Inert gases are also known as noble gases. These elements or gases react under some specific conditions with some specific elements. As we all know that these elements do not react easily so these elements are used in other reactions to block some substitutions and most of these reactions are oxidation and reduction reactions.
The eighteenth group elements of the periodic table are termed as noble gases or the inert gases. The inert gases are known as noble gases because they exist as single atoms, not in pairs.
The eighteenth group elements from the periodic table are:
Helium, Neon, Argon, Krypton, Xenon and Radon.
And in the problem we are provided some elements, the elements which match from the above name list will be counted and noted down to give the answer.
The elements provided are Hydrogen Helium, Neon, Fluorine, Argon, Krypton and Potassium. And the elements which match with the above list are Helium, Neon, Argon and Krypton.
Hence, the number of elements matching with the group eighteenth elements are four.

So, option (D) is correct, 4 .

Note:
As we all know that the noble gases do not react and form products, but under specific conditions such as low temperature and high pressure they are forced to form products, and these products are not much stable to use.