Physics revision

2. what colour is the live wire
4. strongest most penerative wave
8. what is measured in ohms
12. measure of activity per second
13. when an object either gains or loses electric charge in the form of electrons
14. compression rare refraction are included in these
15. time it takes for the activitiy to decrease by half
16. weakest radiation
17. gravity is the universal force of attraction between
19. when a material which is charged come near something which isnt charged it becomes
21. a tiny piece of electricity with hardly any mass
22. middle strengh radiation
23. a tiny particle smaller than an atom

1. thicker in the middle than it is at the edges
3. happens at the boundary between two substances
5. have a high enough frequency to pass through the Earth’s atmosphere to reach geostationary satellites
6. bulb and battery are inculced in one of these
7. light rays can be reflected when travelling from glass into air. Beyond a certain angle, called the .... all the waves refract back into the glass
9. cause of a particle loosing or gaining elecrtons
10. the name given to sound waves that have higher frequencies than 20,000Hz
11. causes a rainbow
12. neutral wire is this colour
18. stop electricity current if any faults occur
20. A subatomic particle of about the same mass as a proton but without an electric charge