1. 1. law of electric charges – the law that states that like charges repel and opposite charges attract

2. electric force – the force between charged objects

3. electric field – the region around a charged object in which an electric force is exerted on another charged object

4. conductor – a material in which charges can move easily

5. insulator – a material in which charges cannot easily move

6. static electricity – the buildup of electric charges on an object

7. electric discharge – the loss of static electricity as charges move off an object

8. cell – a device that produces an electric current by converting chemical energy into electrical energy

9. battery – a device that is made of one or more cells and converts chemical energy into electrical energy

10. potential difference – the energy per unit charge; specifically, the difference in energy per unit charge as a charge moves between two points in the path of a current (same as voltage); expressed in volts

11. photocell – the part of a solar panel that converts light energy into electrical energy

12. thermocouple – a device that converts thermal energy into electrical energy

13. current – a continuous flow of charge caused by the motion of electrons; the rate at which charge passes a given point; expressed in amperes

14. voltage – the difference in energy per unit charge as a charge moves between two points in the path of a current (same as potential difference); expressed in volts

15. resistance – the opposition to the flow of electric charge; expressed in ohms

16. electric power – the rate at which electric energy is used to do work; expressed in watts

17. circuit – a complete, closed path through which electric charges flow

18. load – a device that uses electrical energy to do work

19. series circuit – a circuit in which all parts are connected in a single loop

20. parallel circuit – a circuit in which each load is placed on a separate branch