1. Thermal Energy The energy of moving particles in matter. The hotter the particles are, the more thermal energy they produce.

2. Heat Everything has heat. The more molecules something has, the more heat energy it has. Even if one object is colder than another, the colder object can still have more heat energy if it has more molecules.

3. Friction Friction is the force that slows down moving objects. When two things rub together, they create friction. On a bike, there are two pieces of hard rubber that push against the tire when the brakes are engaged. The pieces of rubber rub against the tire, slowing it down to a halt. Friction creates heat.

4. Temperature The measure of how hot or cold something is.

5. Thermometer A tool that measures how much heat something has. A thermometer measures the temperature of something, showing how hot or cold it is. There are many different types of thermometers that measure the temperature of different things. We use thermometers to measure the temperature of the air, our bodies, food, and many other things.

6. Conductors Any material that allows heat to move through it easily.

7. Insulators Any material that does not allow heat to pass through it easily.

8. Convection

9. Conduction The way heat travels through solids.

10. The third method of heat transfer How does heat energy get from the Sun to the Earth? There are no particles between the Sun and the Earth so it CANNOT travel by conduction or by convection. ? RADIATION Radiation

11. Solar Energy Energy from the sun