Across
1
Tectonic landmass section
4
Gas form of a liquid
5
Path of a planet around the sun
6
Push or pull on an object
8
Center of an atom or cell
12
Blocking of light by a celestial body
Down
2
Icy body with a tail near the sun
3
Reddish electrical conductor
7
Positive particle in nucleus
9
Preserved remains of ancient life
10
Fourth state of matter
11
Gas essential for breathing
13
Nerve cell in the brain