1.1 Introduction to The Particulate Nature of Matter and Chemical Change

Which of the following best describes the particle arrangement in a solid?

A. Particles are closely packed and vibrate in fixed positions.

B. Particles move freely and are far apart.

C. Particles slide past each other and are closely packed.

D. Particles have high energy and move randomly.

Which process involves the direct change from a solid to a gas?

A. Melting

B. Boiling

C. Sublimation

D. Condensation

Which of the following is NOT a postulate of the atomic theory?

A. All matter is composed of tiny indivisible particles called atoms.

B. Atoms of the same element are identical in size, mass, and properties.

C. Atoms can be subdivided, created, or destroyed.

D. Atoms combine in simple whole-number ratios to form compounds.

What is the significance of the random motion of particles?

A. It proves the existence of gravitational forces.

B. It provides evidence for the existence of atoms and molecules.

C. It explains the process of sublimation.

D. It describes the behaviour of gases under pressure.

Which of the following processes involves an endothermic energy change?

A. Condensation

B. Freezing

C. Sublimation

D. Deposition

a) Describe the differences in particle arrangement and energy in solids, liquids, and gases. [4]

b) Provide an example of a substance in each state and the conditions for their existence. [3]

a) Define the terms 'element', 'compound', and 'mixture'. [3]

b) Explain the significance of the atomic and molecular theory in understanding the nature of matter. [4]

a) Describe the postulates of the kinetic molecular theory as it relates to gases. [4]

b) How does the random motion of particles provide evidence for the existence of atoms and molecules? [3]

a) Explain the concept of gas pressure in terms of particle motion and collisions. [3]

b) How does a change in temperature affect the pressure of a gas, assuming the volume is kept constant? [2]

c) Why does the pressure inside a sealed container increase when it is heated? [2]

a) Define the term 'phase transition' and list the processes involved in it. [3]

b) What is the energy change involved when a solid turns into a liquid? [2]

c) Describe the significance of the random motion of particles in a liquid state. [2]