1. FORMS OF ENERGY

2. In science, the word ENERGY means the ability to move or change matter (do work). We cannot directly see energy, but everything we do involves energy (getting up, going to school, figuring out our math problems and doing chores at home).

3. Law of Conservation of Energy: energy cannot be created or destroyed, but it can be changed from one form to another. 1)Thermally, when a warmer object is in contact with a cooler one 2)Mechanically, when two objects push or pull on each other over a distance 3)Electrically, when an electrical source such as a battery or generator is connected in a complete circuit to an electrical device 4)By electromagnetic waves.

4. Whenever energy changes from one form to another, some energy is always converted to heat. Some systems transform energy with less loss of heat than others.

5. There are several different forms of energy. Each one however either causes or can cause matter to move or change. Mechanical Thermal (heat) Electrical Sound Electromagnetic (light) Nuclear Chemical

6. Review: Mechanical energy = The kinetic or potential energy of objects. A moving hammer has mechanical energy. When it hits the nail, it causes the nail to move. What type of ME is that?

7. SOUND ENERGY involves vibrating objects. The drummer is hitting the drumheads with drumsticks, which causes the drumheads to vibrate. The vibrations pass to surrounding air particles and then from one air particle to another in a wave of energy called sound energy.

8. When something vibrates it causes the air around it to vibrate as well. These vibrations may travel to our ear. Our brain interprets these vibrations as sound.

9. How? The vibrations travel through the air to our ear, are sensed by our ear drum which moves little bones, causing fluid in a canal to move tiny sensor hairs. Our brain senses the motion of these hairs as sound.

10. THERMAL ENERGY exists because objects have heat. Heat is caused by the motion of the tiny particles that make up everything. Everything is made up of atoms and molecules that are always in motion. The faster the objects move, the hotter they are.

11. When an object absorbs thermal energy, the molecules and atoms that make up that object move faster and its temperature rises. Thermal energy always flows from a region of higher temperature to a region of lower temperature.

12. Adding and subtracting thermal energy can also change matter from one form to another by making molecules move faster or slower.

13. Electrons are negatively charged particles in atoms. Moving electrons have a form of kinetic energy called ELECTRICAL ENERGY. A lightning bolt is a powerful discharge of electrical energy. A battery contains stored chemical energy and converts it to electrical energy.

14. This is a diagram of an electric current of electrons moving in a closed (complete) circuit. What do you notice happens when the circuit is open?

15. A battery transfers stored chemical energy as electrical energy in moving charges through wires. For example, electrical energy is transferred to the surroundings by the lamp as light energy and thermal energy. Chemical  Light & Heat

16. Electrical energy (EE) can be produced from a variety of energy sources and can be transformed into almost any other form of energy. A bulb converts EE into light energy. A speaker converts EE into sound energy. A windmills converts mechanical energy to EE. Waterfalls convert ME to EE. Nuclear power plants convert nuclear energy to EE. To produce electricity, a heat source is needed to create the conditions in which electrical currents form (burning fossil fuels or renewable energy)

17. CHEMICAL ENERGY= the energy stored in the bonds between atoms that make up compounds. It is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. Some chemical reactions release energy. For example, when an explosive goes off, chemical energy stored in it is transferred to the surroundings as thermal energy, sound e nergy and kinetic energy.

18. More Examples of Chemical Energy: 1)Photosynthesis: process in which plants convert light energy into chemical energy, which can that can be later released to fuel the organisms' activities. 2)Cellular respiration: process used by animals to convert food molecules (glucose) into CO2 and water, and release the chemical energy to the cell. 3)Fossil fuels: coal, oil, and natural gas formed from prehistoric plants and animals; release stored chemical energy when used.

19. ELECTROMAGNETIC ENERGY= energy that travels in electromagnetic waves. Comes from the Sun. Includes radio waves, microwaves, infrared, visible light, UV light, X-rays, and Gamma rays.

20. NON-RENEWABLE RESOURCES: resources that cannot be replaced once they are used up; includes fossil fuels (coal, oil, and natural gas) and nuclear energy.

21. RENEWABLE RESOURCES: a resource which is replaced naturally and can be used again. - Oxygen, fresh water, solar energy, timber & biomass; includes products such as wood, paper & leather.

22. “GREEN ENERGY” energy that does not pollute the environment, - Solar energy, water and wind power are sources of “green energy.”