Q. The average kinetic energy of a helium atom at $30℃$ is
A) Less than $1\ eV$
B) A few $keV$
C) $50 - 60\ eV$
D) $13.6\ eV$
Explanation
(a) Average kinetic energy $E = \frac{f}{2}kT = \frac{3}{2}kT$
$\Rightarrow E = \frac{3}{2} \times \left( 1.38 \times 10^{- 23} \right)(273 + 30) = 6.27 \times 10^{- 21}J$
$= 0.039eV < 1\ eV$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.