Heat energy tends to flow
away from a hotter object to
cooler surroundings
Radiation
Infrared radiation
Emission of electromagnetic
waves
An object that is hotter than its
surroundings emits more
radiation than it absorbs.
Therefore cooling down
Dark, matt surfaces absorb
more infrared radiation than
light shiny surfaces
Shiny surfaces keep heat in
Dark, matt surfaces absorb light in
Kinetic theory
Describes how particles move in
different states
Solids
Strong forces of attraction hold
the particles together in a fixed
regular arrangement
Liquids
Weaker forces of attraction than a solid. Although they are close together
they move around each other and form irregular aggangements. They
have weak intermolecular bonds
Gases
There are almost no forces of attraction between the particles, they
have more energy than the other two states and are free to move in
often random directions at high speeds
Specific heat capacity
Working out how much energy an object can store
The equation is E = m x c x θ
E= energy transferred m=
mass (kg) c= specific heat
capacity θ= temperature
change
Conduction + convection
Convection
This occurs when more energetic particles
move from a hotter region to a cooler
region and take heat energy with them
Conduction
Occurring mainly in solids,
the process is where
vibrating particles pass on
extra kinetic energy to
neighbouring particles
Metals are good conductors due
to free electrons in their outer
shell
Condensation+
Evaporation
Condensation
When a gas turns to a liquid
it is because as it cools the
particles in the gas slow
down and lose kinetic
energy. The attractive
forces then pull the
particles together
Evaporation
When a liquid turns to a gas it
is because the particles have
enough kinetic energy that
they are able to overcome the
other attractive forces of the
liquid and exit the liquid. Then
becoming a gas
B- Electricity + waves
Waves
Longitudinal waves
Longitudinal waves have vibrations
along the same line, as the vibrations
are parallel to the direction of energy
transfer of the wave
Wave speed = Frequency x
Wavelength
Transverse waves
Transverse waves have sideways
vibrations, perpendicular to the direction
of energy transfer of the wave