Light

2. / something, such as an intermediate course of action, that occupies a position or represents a condition midway between extremes.
4. / number of occurrences per unit time.
5. / electromagnetic radiation with wavelengths between 400 and 700 nm that is visible.
7. / change in direction of light ray when passing one medium to another.
8. / single disturbance moving through a medium or field.
9. / a discrete particle, such as a photon or an electron.
11. / non-material property capable of causing changes in matter.
12. / the property of matter and electromagnetic radiation that is characterized by the fact that some properties can be explained best by wave theory and others by particle theory.

1. / change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated.
3. / of or relating to the range of invisible radiation wavelengths from about 4 nanometers.
6. / of or relating to the range of invisible radiation wavelengths from about 750 nanometers.
10. / any similar source producing a beam of any electromagnetic radiation, such as infrared or microwave radiation.