Across
1
Tectonic landmass section
3
Push or pull on an object
4
Second lightest element
5
Fourth state of matter
7
Blocking of light by a celestial body
9
Center of an atom or cell
11
Form of thermal energy
12
Nerve cell in the brain
Down
2
Biological catalyst
3
Preserved remains of ancient life
6
Particle of light
8
Tissue that contracts for movement
10
Disturbance that transfers energy