Chapter 1, Problem 1B.1BE

(i)

Interpretation Introduction

Interpretation: The ratio of the mean speeds of $\text{He}$ and $\text{Hg}$ atoms at $25°\text{C}$ has to be calculated.

Concept introduction: The expression for the mean speed is derived from Maxwell Boltzmann distribution.  The mean speed for the gas particles is represented as,

  $v_{\text{mean}}={\left(\frac{8RT}{\pi M}\right)}^{1/2}$

(ii)

Interpretation Introduction

Interpretation: The ratio of the mean translational kinetic energies of $\text{He}$ and $\text{Hg}$ atoms at $25°\text{C}$ has to be calculated.

Concept introduction:

Kinetic energy is related to the translational motion of the system with respect to some reference (mostly earth).  It is directly related to the temperature.  It is given by the expression,

  $\frac{1}{2}m{v}^2$