STATES OF MATTER
MATTER
• Affected by
temperature and
pressure
• A change in
temperature and/or
pressure can
change the state of
matter of a
substance
Kinetic Theory:
how particles in matter behave
Three assumptions
1. All matter is made of small particles atoms, molecules and ions
2. These particles are in constant motion.
The motion has no pattern.
3. These particles are colliding or crashing
into each other and into the walls of
their container.
Thermal Energy
• Thermal energy is the total energy of the
particles in a material.
• Thermal energy includes kinetic energy
and potential energy
• Solid particles do not appear to be moving
but they are! Solid particles move slowly.
Absorb or Release
Thermal Energy
• When particles absorb thermal energy then
– Temperature increases or
– Temperature remains constant and particles
transition to more energetic phase of matter
• When particles release thermal energy then
– Temperature decreases or
– Temperature remains constant and particles
transition to less energetic phase of matter
Temperature
• Measure of the
average kinetic
energy of the
vibrating or moving
atoms or molecules of
a substance
• Absolute zero= no
movement
• Heat= the total kinetic
energy of a substance
Pressure
• the force per unit area
applied on a surface in a
perpendicular direction
These gas molecules are constantly moving in random
directions. When a molecule hits the container wall (green),
it exerts a tiny force on the wall. The sum of these tiny
forces, divided by the interior surface area of the container,
is the pressure.
One atmosphere is defined as the pressure caused by the
weight of all the overlying air at sea level
or 14.7 pounds per square inch (psi).
Solid
http://www.chem.purdue.edu/gchelp/liquids/character.html
http://www.chem4kids.com/files/matter_solid.html
• Low Temperature and/or High Pressure
• Low Kinetic energy
• Definite pattern resulting in definite volume
and definite shape
• Can be an atom, ion or molecule
• Usually in crystalline form, although some
are glass
Itl.chem.ufl.edu/2045_s00/lectures/fg11_001.GIF
Liquid
http://www.mcwdn.org/chemist/liquids.html
http://www.chem.purdue.edu/gchelp/liquids/character.html
• Less Pressure, More Kinetic Energy
• Definite volume, no definite shape
• Melting point= the vibrations of the
particles cause the forces holding the solid
together to break
• These forces are called attractive forces.
Itl.chem.ufl.edu/2045_s00/lectures/fg11_001.GIF
Gas
http://www.mcwdn.org/chemist/gases.html
http://www.chem.purdue.edu/gchelp/liquids/character.html
• Least pressure, most kinetic energy
• No definite shape, no definite volume
• Evaporation is the boiling point of the liquid
• Gravity – prevents escape of gases
• Gas would escape to space if not for the Earth’s
gravity
Itl.chem.ufl.edu/2045_s00/lectures/fg11_001.GIF
Plasma
• Hot ionized temperatures
above 5000°C
• Violent collisions
cause electrons to be
knocked off
• Stars, lightning, neon signs,
solar wind, auroras, comet tails,
welding arcs, fireball made by
nuclear weapons
http://dewa.com/animated/
Condensation
http://en.wikipedia.org/wiki/Condensation
• Change in matter to …
a denser stage through colder
temperatures or more pressure
http://en.wikipedia.org/wiki/Condensation
• Gas phase to a liquid phase
http://ga.water.usgs.gov/edu/watercyclecondensation.html
Sublimation
• Skip a Phase: Solid-->Gas
• Carbon dioxide (dry ice), Naphthelene
(moth balls) and snow sublime
http://ga.water.usgs.gov/edu/watercyclesublimation.html
http://ga.water.usgs.gov/edu/watercyclesublimation.html
http://www.windows.ucar.edu/tour/link=/comets/sublimation.html&edu=high
Conservation of Matter and Energy
• During an ordinary chemical change,
there is no detectable increase or
decrease in the quantity of matter.
LAW
• Energy cannot be created or destroyed,
it can only change its form.
http://dewa.com/animated/
Phase Change
From a
To a
Absorbs or
Releases
Thermal Energy
Condensation
gas
liquid
releases
liquid
solid
releases
solid
liquid
absorbs
liquid
gas
absorbs
solid
gas
absorbs
Freezing
Melting
Evaporation
Sublimation
Absorb or Release Thermal
Energy?
http://www.cmmacs.ernet.in/~himesh/Hydrosphere%20Components.gif
Recap of Phase Changes
• Melting – Solid to
• Freezing – Liquid to
• Evaporation – Liquid to
• Condensation – Gas to
• Sublimation – Solid to