Title: Kinetic Molecular Theory

Brownian motion, Kinetic theory, Thermal conduction

Use the postulates of the kinetic theory to explain the following:

i)Matter can exist in three states

ii)The pressure exerted by a confined gas decreases as its temperature is lowered

iii)A gas of low molecular mass will diffuse through air faster than a gas of high molecular masseven though both are at same temperature.

The Kinetic Theory can be used to describe the three physical states of matter namely, solid, liquid and gas. In this theory, some basic assumptions has to be made:

a) all matter is made up of extremely small particles

b) these particles are in constant random motion

c) all collisions between these particles are elastic, and

d) mutual attractive forces exist between particles

The explanation below gives more information about the three states of matter:

i) solids

> particles are held together in a regular pattern by strong attractive


> particles vibrate about in fixed positions.

ii) liquids

> vibrating particles have sufficient energy to move from their

fixed positions to other parts within a liquid.

> liquids take the shape of their container.

iii) gases

> particles have sufficient kinetic energy to help escape the

attractive forces from other particles.

> gases take up the complete volume of a container.

The kinetic theory provides vital information on the sciences we learn. An example of this is the topic on "heating and cooling" in physics. Besides, the kinetic energy theory may also be used in application to many other things, one of which is in relation to gas laws.

Pressure is explained by the Kinetic Theory as arising from the force exerted by collision of gas molecules with the walls of the container.

An experiment was conducted by a French scientist, Jacques Charles to see the effect of temperature on the pressure of a gas being confined in a container. It was found that when the temperature went down, the pressure also went down and vice-versa with the...
tracking img