waves

2. unit of frequency, its abbreviation is Hz. Its equal to one vibration every second.
4. wide stream of light rays, all moving the same direction.
5. high energy electromagnetci radiation produced during nuclear reactions. They have no mass and travel at the speed of light.
7. allowing light to come through imperfectly
9. material through which a wave moves.
10. maximum distance that a particle moves away from its undisturbed position.
12. a lense curved outwards.
13. change in the speed of light as it passes from one substance into another. It usually involes a change in direction.
14. describes a substance that does not allow any light to pass through it

1. high energy electromagnetic waves that can be transmitted through solids and provide information about their structure
3. allows most light to pass through it, objects can seen clearly through transparent sunstances.
6. invisible radiation emmitted by all warm objects.
8. region in which the particles are closer together than when not disturbed by wave.
11. transmitter of energy without the movement of particles from place to place. The vibration of particles or energy fields is involed.
12. a lense curved inwards.
13. narrow beams of light.