- Energy is something that makes a change. Making a change is called "doing work."
- Scientists define energy this way: Energy is the ability to do work.
- The total amount of energy in the universe always has been and always will be the same.Humans use energy. We do not make energy, but do work by changing energy from one type to another.
Energy comes in many different forms.
- Energy has many different forms. These are the most common:
- Solar energy - energy that comes from the sun
- Heat energy - occurs when the heat from one object moves to another
- Light energy - comes from light bulbs or LED
- Chemical energy - energy released when one substance changes to another like wood burning or metal rusting
- Mechanical energy - the motion of machines
- Electrical energy - energy caused by moving electrical charges from one place to another
- Energy can be transferred, but it cannot be created or destroyed.
- When energy is used, it changes from one form of energy to another.
- Example: When coal is burned, its energy is changed into heat and light.
- When energy is used, it changes from one form of energy to another.