Across
1
Blocking of light by a celestial body
4
Biological catalyst
7
Smallest unit of an element
8
Gas form of a liquid
11
Natural satellite of Earth
12
Solid with repeating atomic pattern
Down
2
Second lightest element
3
Push or pull on an object
5
Fourth state of matter
6
Preserved remains of ancient life
9
Tissue that contracts for movement
10
Path of a planet around the sun
13
Particle of light