Chapter 8.4, Problem 8.8CE

Interpretation Introduction

Interpretation:

Way in which packing of $Li$ and $He$ atoms has to be determined from its densities. Also the concept of kinetic-molecular theory where this comparison applies has to be given.

Concept Introduction:

Kinetic-molecular theory of gases:

Properties of gases are different from solids and liquids.  When pressure is applied to gases, they are easily compressed to smaller volume and they have low densities.  These properties can be explained by a theory called kinetic-molecular theory.

The four assumptions of this theory are given below:

• Gases are made up of particles like atoms or molecules which randomly move and there will be no attractive forces between them.
• Comparing the space occupied by the gas particles and the space between particles, the former is much smaller than the latter.
• The average kinetic energy of gas particles and the Kelvin temperature is proportional.
• There is an elastic collision between gas particles or with the wall of their container and thus no energy is lost during collision and total kinetic energy of the particles is constant.

Density can be calculated by the equation given below:

  $\text{d = }\frac{\text{m}}{\text{V}}$

Where,

d is the density

m is the mass

V is the Volume