Across
- 3. something that does not give off light
- 4. the presence of something
- 5. not allowing light to pass through
- 7. allows some light through
- 8. imaginary surface
- 12. something that happens when light hits a surface
- 13. a source of radiation
- 15. where the incident ray hits
- 18. something that reflects light back in the dark
Down
- 1. something gives out light
- 2. the new direction is called the
- 6. the emission of visible light
- 9. allowing light to pass through
- 10. 100 watts of energy
- 11. doesn't need matter to transfer energy
- 13. flat surface
- 14. when light shines on an object this appears behind it
- 16. something that reflects light from the sun
- 17. can be artificial or natural