Thermal energy is the energy of moving particles within matter. Heat transfers from warmer objects to cooler ones through three processes: conduction, convection, and radiation. Conduction involves direct contact, where heat transfers between touching objects due to differences in temperature. Convection involves the transfer of heat by the circulation of fluids like air and water. Radiation transfers heat through electromagnetic waves without direct contact between the objects.

1. The Transfer
of Heat

2. Thermal Energy
• Energy is the ability to make things move or
change.
• All matter (anything with mass that takes up
space) is made up of tiny particles that are
always moving.
• Thermal energy is the energy of the moving
particles. This energy is felt as heat.
Thermal Energy = Heat

3. Heat
• Heat ALWAYS moves from a warmer object to
a cooler one. This movement is called heat
transfer.
• As heat moves into an object, it becomes
warmer. As heat moves out of an object, it
becomes cooler.

4. Heat Transfer
• When a freshly made
cup of coffee is sitting on
a counter, it will lose
heat because the air
around it is cooler than
the coffee.
• When an ice cube is
sitting on a table, the
warmth in the air will
transfer into the ice
cube, melting it.

5. Heat Transfer
• There are 3 ways that heat can transfer to
other objects. These methods of transfer are
called conduction, radiation, and convection.

6. Conduction
• Conduction is the
transfer of heat between
things that are touching.
• When two things that
are touching have
different temperatures,
heat will move from the
warmer object to the
cooler one.
Examples:
• Hands are warmed when holding a hot
mug of cocoa
• A hot stove burner warms a pot sitting
on it.
• Can you think of some other examples?

7. Conductors
• Conductors are objects that allow
heat to move through them easily.
• Metals are good conductors
because they allow heat to move
through them easily. Examples of
metals include iron, silver, copper,
aluminum, and stainless steel.
• For example, if you were at a
campfire and you put a stick in the
fire, your hand would not burn.
Wood is not a good conductor. If
you left a metal spoon in a hot pot
on the stove and held the spoon,
your hand would burn.

8. Convection
• Convection is the
transfer of thermal
energy through
liquids or gases.
• Warmer air and
water rises and
cooler air and water
sinks. This creates a
convection current.
Click the picture below
for a convection
demonstration.

9. Radiation
• Radiation is the transfer of energy through
electromagnetic waves.
• Radiation from the sun heats objects on Earth.
Heat travels from fire to objects through
radiation as well.

10. Thermal Energy Review