What is Energy?

What are the different forms
of Energy?
What is Energy?

• The ability to do work
Can you make
things move?
• Then you have
energy…
• …but there are seven
different kinds of
energy…
1. Heat Energy
• The random motion, or
vibration, of atoms in
matter
• The faster the atoms
vibrate the more heat
energy they have
2. Chemical Energy
• What holds atoms in
molecules together
• Can be released by
chemical reactions like
burning wood
3. Electrical Energy
• The movement of
electrons through
matter
• Electricity is a form of
electrical energy
4. Light Energy
• The energy carried by
light
• Yes, whenever you are
looking at light, you are
looking at energy
5. Mechanical
Energy
• The energy of moving
things
• When you ride a bike
you use mechanical
energy
6. Nuclear Energy
• Holds protons and
neutrons together in an
atom’s nucleus
• Powers the sun and
nuclear power plants
(reactors)
7. Sound Energy
• Vibrates air molecules
• The air molecules move
tiny bones in your ear
• The message of sound
then moves to your brain
• Can also vibrate objects
The Law of Conservation
of Energy:
Energy can change form,
but can’t be created nor
destroyed.
So energy is always conserved, it
is never "lost" or "wasted“.
Chemical energy in
gasoline is changed to
heat energy and then to
mechanical energy in a
car.
Mechanical energy to sound energy
and some lost thermal energy
Kinetic energy to electrical energy
Chemical energy stored in
explosives is transferred to the
surroundings as thermal energy,
sound energy and kinetic
energy.
Chemical energy to potential energy
and kinetic energy
Electrical energy to sound energy
and some lost thermal energy
The battery transfers stored
chemical energy as
electrical energy. The
electrical energy is transferred
to the surroundings by the lamp
as light energy and thermal
Energy
transfer
Nuclear energy to thermal energy

For 9th grade physics, chapter 6 "Energy transformations and energy transfers"