This document describes the kinetic particle theory and the changes of state between solids, liquids, and gases. It explains that all matter is made of particles in constant motion. In solids, particles are packed closely together in a fixed pattern, in liquids they are more loosely packed but still in contact, and in gases they are far apart with little attraction. Changes between these states, like melting, boiling, condensation, and freezing occur when heating or cooling causes particles to gain or lose energy and change their motion and arrangement. The document provides detailed explanations of each state and phase change using the kinetic particle theory model.

1. CHAPTER 1:
SOLI DS, LI QUI DS and
GASES
1

2. WHAT WE WILL BE
LEARNING
 Describe the arrangement and properties of
solid, liquid & gaseous states of matter using
Kinetic Particle Theory
 Explain the inter- conversion of the 3 states of
matter in terms of Kinetic Particle Theory and of
the energy changes.
2

3. WHAT IS MATTER MADE
OF ?
 Matter is anything that occupies space and has
mass.
• It can exist as a solid, a liquid or a gas.
Recall :
1) Solids
• It has a definite shape and volume.
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4. 2) Liquids
• It has a definite volume but
no definite shape.
• It takes the shape of the container.
3) Gases
• It has no definite shape and volume.
• It can be compressed and take the
shape of the container.
4

5. KINETIC PARTICLE
THEORY
 The differences in the properties of solids,
liquids and gases can be explained in terms of
the Kinetic Particle Theory.
Theory
• This theory states that all matter is made up of
tiny particles and are always in constant
random motion.
5

6. 1) Solids
• The particles are packed very closely together in
a fixed, regular pattern.
pattern
 This is why crystals have flat
faces, straight edges and
sharp points.
• The particles attract one another
strongly, thus they are in
strongly
fixed positions.
 This gives solid a definite
volume and a definite shape.
6

7. • The particles are not free to move about but can
only vibrate gently about their fixed positions.
positions
 This is why solid cannot be compressed.
• There is very little empty space between the particles.
 This is why solid has high density.
7

8. 2) Liquids
• The particles are packed closely together, but
together
not as close as those particles in solids.
 This explains why liquid
cannot be compressed.
• The particles are held together
by forces of attraction
between them.
 This explains why liquid
has a definite volume.
8

9. • The particles are not arranged in a fixed pattern
and they are free to move about within short
distances (in between each other and throughout
the liquid).
 This is why liquid has no definite shape.
 They flow and take the shape
of the container.
9

10. 3) Gases
• The particles are far apart from each other and
there is so much space between
each particle.
particle
 This explains why gas can
be compressed easily
and has low density.
• The particles have little attraction
for one another.
 This explains why gas has no definite volume.
10

11. • The particles are not arranged in a fixed pattern
and they move about randomly.
randomly
• They can spread out rapidly to fill up a container.
 This is why gas has no definite shape.
11

12. CHANGES OF STATES
 Matter can change its state.
• This change in state is reversible.
reversible
Process
Changes from …
Brief Description
Melting
solid to liquid
Heating causes particles in the
solid to vibrate more until they
break free from their fixed
position.
Boiling/
liquid to gas
Heating causes particles in the
liquid to gain energy to move
faster and further apart.
Eventually they break away
from surrounding particles and
form gas.
Vaporization
12

13. Process
Changes from
Brief Description
Condensation gas to liquid
Energy is removed from the
gas particles. This causes
them to slow down and
enter the liquid state.
Freezing
liquid to solid
Particles lose heat, slow
down and get locked into
position.
Sublimation
Solid to gas
Solid changes into gas
without going through the
liquid state.
13

14. I ) Melt ing
 Melting is a process in which a solid changes into a
liquid.
 Heat is absorbed
during melting.
 Melting takes place at
a fixed temperature
called the melting point.
point
temperature
stearic acid
water at 100ºC
14
HEAT

15. Heating curve for changing a Solid to a Liquid
Temperature /oC
Melting
completes
Melting
starts
Melting
Point of
Substance
Solid + Liquid
Solid
Liquid
Time /min
15

16. II) B
oiling
 Boiling is a process in which a liquid changes into
a gas.
gas
 This change in state occurs inside the liquid.
liquid
 Heat is absorbed during boiling.
 Boiling takes place at a fixed temperature called
the boiling point.
point
16

17. Heating curve for changing a Liquid to a Gas
Temperature /oC
Boiling
completes
Boiling
starts
Boiling
Point of
Substance
Liquid + Gas
Liquid
Gas
Time /min
17

18. I V) Sublimat ion
 Sublimation is a process in which a solid changes
into a gas without passing through the liquid
phase.
phase
 Heat is absorbed during sublimation.
 Sublimation takes place at a fixed temperature.
Examples: Dry ice, iodine,
ammonium chloride
18

19. V) Condensat ion
 Condensation is a process in which either
a gas changes into a liquid or
a gas changes into a solid.
solid
 This change in state occurs when a gas is cooled
to its boiling point.
 Heat is evolved during condensation.
 Condensation takes place at a fixed temperature
numerically equal to its boiling point.
19

20. Cooling curve for changing a Gas into
a Liquid
Temperature /oC
Condensation
starts
Boiling
Point of
Substance
Gas
Condensation
completes
Liquid + Gas
Liquid
Time /min
20

21. VI ) Fr eezing
 Freezing is a process in which
a liquid changes into a solid.
solid
 Heat is evolved during freezing.
 Freezing takes place at a fixed temperature called
the freezing point.
point
 Freezing point and melting point have the same
numerical value.
21

22. Cooling curve for changing a Liquid
into a Solid
Temperature /oC
Freezing
starts
Freezing
Point of
Substance
Freezing
completes
Liquid
Liquid + Solid
Solid
Time /min
22