Across
1
Element found in all living things
3
Blocking of light by a celestial body
4
Glass that splits light into spectrum
8
Nerve cell in the brain
10
Force that attracts objects together
Down
2
Center of an atom or cell
5
Particle of light
6
Gas form of a liquid
7
Infectious microscopic agent
9
Ball of burning gas in space
11
Measure of matter in an object