Kinetic Molecular Theory Grade 8

Which of the following is definitely true according to the Kinetic Molecular theory? (mark all that apply)

• $\frac{1}{2\ }mv^{2\ }\propto T$

• All matter is made up of molecules

• All molecules are made up of atoms

• There is intermolecular space between molecules.

• The intermolecular force of attraction depends on the intermolecular space.

Molecules of a substance are

• Always alike

• Usually alike

• Not necessarily alike

• It doesn't matter. All protons are the same!

In which season will you reduce the pressure in your car tyres?

• Winters

• Monsoon

• Summers

• None

Force of cohesion and force of adhesion are types of

• Intermolecular space

• Gravity

• Intermolecular force of repulsion

• Intermolecular force of attraction

This is a 3D model that Piyush made. The box in which it has to be packed is, unfortunately, a little smaller than the size of the model. The model is made up of iron balls. Which of these does Piyush do to make the model fit?

• Heats it a little

• Freezes it for 30 minutes

The kinetic energy of a molecule is _____________ proportional to Temperature.

• directly

• inversely

The pink space indicates

• Pressure

• Intermolecular space

• Intermolecular attraction

Sandhya has made her notes on the kinetic molecular theory, but not everything is correct. Mark everything that is incorrect.

• The molecules of a substance are alike.

• The molecules of different substances differ in size, shape, properties etc.

• ALL molecules move faster when heat is applied and slow down when heat is withdrawn.

• Force of cohesion is between dissimilar molecules and Force of adhesion is between similar molecules.

The Kinetic Molecular Theory is applied in all of the following. Except ONE. Which one?

• Refrigeration

• Tyre Pressure in Cars

• Diffusion of gases in an area

• Uranium Enrichment

• None. They are all examples of application of KMT.

The energy of movement is ___.

• potential energy

• kinetic energy

• mechanical energy