CHAPTER 2

The Structure

Of The Atom

MATTERMatter is anything that has mass and occupies

space.It is made up of tiny particles which are discrete

and always in motion.This particles can be atoms, molecules or ions.Atom is the smallest, indivisible particle that can

take part in a reaction.Molecules consist of 2 or more elements

combined together chemically.Ions are particles that are charged due to loss or

gain of electrons.Anions are negatively charged particles and

cations arePositively charged particles

THE KINETIC THEORY OF MATTER

The Kinetic Theory of

Matter

Matter is made up of discrete and tiny particles that occupies space

The particles always vibrating and moving about randomly

The particles obtain higher kinetic energy and move in more rapid when the temperature of the matter increases

The particles collide with each other and bounce off in all direction

Matter can exist in 3 physical states:a) Solidb) Liquidc) Gas

Matter can undergo a change its state of matter when heat is supplied or released from it.

THE HEATING CURVEHeat energy

absorbed by the particles causes the particles to vibrate faster.

The kinetic energy increases.

The temperature increases.

The substance exists in solid state.

Heat energy absorbed by the particles is used to overcome the forces of attraction between particles so that the solid turns to liquid.

The temperature remains constant.

This temperature is known as the melting point.

Heat energy is absorbed by the liquid particles.

The particles move faster.

The temperature increases.

Heat energy absorbed by the particles is used to overcome the forces of attraction between particles so that the liquid turns to gas.

The temperature remains constant.

This temperature is known as the boiling point.

THE COOLING CURVEThe particles in the gas lose their kinetic energy and move slower.

The temperature decreases.

Heat is lost/released to the surroundings.

Heat given out to the surroundings is balanced by the heat energy released as the particles attract one another to form a liquid.

Its temperature remains constant.

The substance exists in liquid and gaseous states.

The particles in the liquid lose their kinetic energy and move slower.

The temperature decreases.

Heat is lost/released to the surroundings.

Heat given out to the surroundings is balanced by the heat energy released as the particles attract one another to form a solid.

Its temperature remains constant.

The substance exists in liquid and solid states.

2.