Question

Degree of freedom of unknown gas is $3$. The gas can be

• A. $H_2$
• B. $O_2$
• C. $C{O}_2$
• D. $He$

Answer 1

The correct option is D $He$

We know that,
$f=3A-B$
where $A=$ No. of independent particles
$B=$ No. of independent restrictions
For $He$ (Monoatomic gas),
$A=1,B=0$
$\therefore f=3\times 1-0=3$