Kinetic Particle Theory

A. Matter

Matter is a substances that has mass and occupies space. Matter can exist as a solid, liquid and gas. These three forms of matter are called the state of matter. Matter can change form one state to another due to change in temperature and pressure.

Table 1.1. Properties State of Matter

State of Matter	Properties
Solid	Has a fixed shape Has a fixed volume Cannot be compressed
Liquid	Has a not fixed shape Has fixed volume Cannot be compressed
gas	Has not fixed shape Has not fixed volume Can be compressed

B. Kinetic Particle Theory

Kinetic particle theory explanation the movement of particle. Kinetic particle theory explanation that all matter is made up of tiny particle and these particle are in constant and random in motion. From the kinetic particle theory we can :

Describe the state of matter
Explain the differences in the properties of solid, liquid and gases
Explain the changes of state

Properties the three state from the behavior particles or the kinetic particle theory

State of Matter	Properties
solid	Arrangement of particle Orderly or closely packed Attractive forces between particle very strong Kinetic energy of particle is very low Particle motion vibrate and rotate about their fixed position
liquid	Arrangement of particle Disorderly and less closely packed than particle in solid Attractive force between the particle is strong The kinetic energy of the particle is low Particle motion slide over each other
Gas	Arrangement of particle Disorderly and very far a part Attractive force between the particles is very low The kinetic energy of the particle is very high Particle motion at great speed and random motion

C. Changes of State and the Kinetic Particle Theory

· Melting Process

Melting is when a substance changes from a solid to liquid.

What happens to the particle of a solid that is heated until it melts?

a. Heat energy is absorbed by the particle solid

b. Heat energy converted into kinetic energy

c. Particle start to vibrate faster about their fixed position

d. Temperature is high,

e. The vibration of the particle become sufficient to overcome the attractive forces between them

f. Particle begin to break away

g. Particle slide over one another

h. Substances changes liquid

Picture 1.1 Heating Curve in Melting Process

· Freezing Process

Freezing is when substance changes from liquid to solid.

What happens to the particle of liquid that is cooled until its freeze ?

a. Heat energy is given out by the particles

b. Particle of liquid lose kinetic energy

c. The particle begin move more slowly

d. The temperature is decrease or low

e. The particle start to settle into fixed position

f. Particle can only vibrate about their fixed position

g. Substances changes to solid

Picture 1.2 Cooling Curve in Freezing Process

· Boiling Process

Boiling is when substance changes from liquid to gas

What happens to the particles of gas that is heated until its boils?

a. Heat energy is absorbed by the particles of liquid

b. Particle gain heat energy and convert into kinetic energy.

c. The particle start to move faster,

d. The temperature rises at boiling temperature

e. Liquid have enough energy to overcome the attractive forces between them

f. Particle spread far apart and move rapidly in all directions

g. Substances changes to gases

Picture 1.3 Heating Curve in Boiling Process

· Condensation Process

Condensation is when substance changes from gas to liquid

What happens to the particles of gas that is cooled until it condenses?

a. Heat energy is given out by the particle of gas

b. Particle lose kinetic energy

c. Particle begin to move more slowly

d. Temperature is low

e. Particle can only slide over each other

f. Substances changes to liquid

Picture 1.4 Cooling Curve in Condensation Process

· Evaporation Process

Evaporation is when substance changes from liquid to gas at temperature lower than boiling point. Evaporation occurs because some particles have enough energy to escape as a gas from the surface of liquid. Liquid that evaporate quickly at room temperature are called volatile liquid. For example : petrol and perfume.

Table 1.2 The Differences between Boiling and Evaporation

Boiling Process

Evaporation Process

Occur only at boiling temperature
Occur throughout the liquid
Occur rapidly

Occur at temperature below boiling temperature
Occur only at the surface of the liquid
Occur slowly

· Sublimation Process

Sublimation is when substance solid changes to gas without liquid

Picture 1.5 The Changes of States of Matter

A. Diffusion

Diffusion is the process by which particles move freely to fill up any available spaces. We can demonstrate diffusion in the laboratory by placing a gas jar of air over a gas jar containing bromine vapor (Picture1.6). A cover is initially placed between the two gas jar to separate the gases. Air is colorless. Bromine vapor is reddish brown and is heavier than air. A few minutes after the cover is removed, the gas in both gas jars looks the same.

This happens because both air and bromine are made up of tiny particles moving at random. The bromine particle diffuse (spread out) into the spaces between the air particles while the air particles diffuse into the spaces between the particles of bromine.

Picture 1.6 Diffusion between Bromine and Air

Gases with lower molecular masses diffuse faster than those with higher molecular masses
The movement of particles from a region of higher concentration to a region of lower concentration.
The higher the temperature, the faster the rate of diffusion