This document discusses four types of energy: chemical energy, which is released during chemical reactions like combustion and is stored in batteries and food; kinetic energy, which all moving objects possess; electrical energy, which powers machines and can be transformed into other forms like light and heat, with sources including fossil fuels, wind, water, and sunlight; and thermal energy, which flows from warmer to cooler substances and can cause changes in state, with the sun being the main natural source of heat on Earth.

1. CHEMICAL ENERGY
• Is released when a chemical reaction occurs.
• Batteries and food are sources of chemical
energy too.
• When a car burns petrol, a chemical reaction
occurs between the petrol and oxygen.
• This chemical energy is then transformed into
kinetic energy.

2. KINETIC ENERGY
• All moving things have kinetic energy.
• This energy is produced through a motion or
movement.
• Living things have kinetic energy.
• Example: moving car, windsurfer or bike when
is in movement.

3. ELECTRICAL ENERGY
• It’s used to power machines.
• We can trasnform it into light, sound, heat and
movement.
• The energy to generate electricity comes from
different sources: fossil fuels, wind, water,
biomass, sunlight, nuclear power stations…

4. THERMAL ENERGY
• It flows from a warm substance to a cooler
substance.
• A change in the thermal energy of a substance
can also make the substance change state.
• The Sun is the main source of heat on Earth.
• Sometimes, we use fossil fuels to warm
houses and cook our food (gas).