Question

At what temperature is the average kinetic energy of an atom in helium gas equal to 6.21 x 10-21 j?

Answer 1

The average kinetic energy of an atom in helium gas at temperature T is given by,

K.E=$\frac{3}{2}KT$

here, K is botzmann constant =1.38×10⁻²³ m² kg s⁻² K⁻¹

Given, K.E= 6.21×10⁻²¹ J

Substituting the values,

$6.21*10^{-21}=\frac{3}{2}1.38*10^{-23}T$

T= 300 K

Therefore, at temperature 300 K the average kinetic energy of the atom in helium gas is 6.21×10⁻²¹ J.