This document discusses the kinetic theory of matter and the states of solids, liquids, and gases. It explains that all matter is made of particles in constant motion and the arrangement and motion of the particles determines the properties of the substance. Solids have a fixed shape and volume, liquids have no fixed shape but fixed volume, and gases have no fixed shape or volume. Changes between states, such as melting and evaporation, occur when the particles gain enough kinetic energy to overcome attractive forces. Brownian motion provides evidence of particles in liquids and gases colliding. Absolute zero is the temperature where gases cannot be cooled further.

1. Kinetic Theory
Solids, liquids and gases

2. States of matter
 Remember, all substances are made
up of tiny particles that are moving.
 The arrangement of these particles
and the way that they are moving
determine the properties of the
material.
 The states of matter are:
◦ Solid
◦ Liquid
◦ Gas

3. Solids
 Fixed shape.
 Fixed volume.
 High density.
 Will not flow.
 Particles in a solid vibrate about a
fixed position. The more energy, (heat)
in the solid, the faster these particles
vibrate.

4. Liquids
 No fixed shape.
 Fixed volume.
 Less dense than solids.
 Will flow.
 Particles in a liquid can move more
freely around each other. As the
liquids is heated, the movement
becomes more energetic.

5. Gases
 No fixed shape.
 No fixed volume.
 Very low density, (allows them to be
compressed).
 Will flow.
 Particles of gas are moving around
randomly all the time. Collisions
between the particles and their
container causes pressure.

6. Changes of state
Melting Evaporation
Sublimation
Solid Liquid Gas
Freezing Condensation

7. Changes of state
 As we heat solids the particles start to
vibrate more – they gain kinetic
energy.
 We notice the increase in kinetic
energy of the particles as an increase
in temperature.
 If the particles are moving rapidly
enough, then the solid will melt.

8. Changes of state
 As we heat liquids the movement of
the particles becomes even more
energetic.
 If the particles move fast enough then
they can break the attractive forces
between the particles and move
independently.
 The liquid evaporates to form a gas.

9. Brownian motion
 Named after the botanist
Robert Brown (1773-1858).
 Observed pollen grains moving
randomly in water.
 Thought it might be due to a “life
force” in the pollen.
 However, also observed the
movement in non-living particles.
 Similar effect can be seen in gases.

10. Brownian motion
 Brownian motion was not explained
until Particle Theory was developed.
 Particles in liquids and gases are
constantly moving and bump into
other particles, such as pollen grains.
 This causes the random movements
of the grain that was observed.
 A good example is the movement of
smoke particles in air.

11. Brownian motion

12. Absolute zero
 Absolute zero is the temperature at
which it is impossible to cool a gas any
further.
 It is approximately -273oC.
 The Kelvin temperature scale starts from
absolute zero:
T = + 273 and = T – 273
(T = temperature in Kelvin, = temperature in Celsius)
YOU NEED TO KNOW THIS!

13. Kinetic Theory
What can you remember?

14. States of matter
 substances
Remember, all substances are made
particles
up of tiny particles that are moving.
 The arrangement of these particles
arrangement
moving
and the way that they are moving
determine the properties of the
material.
 The states of matter are:
Solid
◦ Solid
Liquid
◦ Liquid
Gas
◦ Gas

15. Solids
 Fixedshape.
shape.
 Fixedvolume.
 High density.
density.
 Will not flow.
vibrate
 Particles in a solid vibrate about a
position. heat
fixed position. The more energy, (heat)
faster
in the solid, the faster these particles
vibrate.

16. Liquids
 No fixed shape.
shape.
 Fixedvolume.
volume.
solids.
 Lessdense than solids.
dense
 Will flow.
freely
 Particles in a liquid can move more
freely around each other. As the
heated, heated, the movement
liquids is
energetic.more energetic.
becomes

17. Gases
 No fixed shape.
shape.
 No fixed volume.
volume.
 Very low density, (allows them to be
density,
compressed
compressed).
 Will flow.
 Particles of gas are moving around
Collisions
randomly all the time. Collisions
between the particles and their
pressure.
container causes pressure.

18. Changes of state
Melting Evaporation
Sublimation
Solid Liquid Gas
Freezing Condensation

19. Changes of state
 As we heat solids the particles start to
heat
vibrate more – they gain kinetic
kinetic
energy. energy
 We notice the increase in kinetic
temperature.
energy of the particles as an increase
in temperature.
particles
melt.
 If the particles are moving rapidly
enough, then the solid will melt.

20. Changes of state
 As we heat liquids the movement of
heat movement
the particles becomes evenenergetic.
more
energetic.
particles
attractive
 If the particles move fast enough then
they can break the attractive forces
independently.
between the particles and move
independently.
evaporates gas.
 The liquid evaporates to form a gas.

21. Brownian motion
 Named after the botanist
Robert Brown (1773-1858).
 Observedpollen grains moving
pollen randomly
randomly in water.
a “life
 Thought it might be due to “life force”
force” in the pollen.
 However, also observed the
non-living in non-living particles.
movement
 Similar effect can be seengases.
in gases.

22. Brownian motion
 Brownian motion was not explained
Particle Theory
until Particle Theory was developed.
 Particles in liquids and gases are
constantlymoving and bump into
moving
particles,
other particles, such as pollen grains.
random
 This causes the random movements
of the grain that was observed.
 A good example is the movement of
smoke particles in air.

23. Brownian motion

24. Absolute zero
 Absolute zero is the temperature at
which it is impossible to cool a gas
any further.
-273oC.
 It is approximately -273oC.
 The Kelvin temperature scale starts
Kelvin
from absolute zero:
T = + 273 and = T – 273
(T = temperature in Kelvin, = temperature in
Celsius)
YOU NEED TO KNOW THIS!