Across
1
Unit of energy
4
Particle of light
6
Tissue that contracts for movement
7
Element found in all living things
8
Push or pull on an object
12
Curved glass that refracts light
Down
2
Blocking of light by a celestial body
3
Compound containing oxygen
5
Gas form of a liquid
9
Infectious microscopic agent
10
Smallest unit of an element
11
Positive particle in nucleus