Across
1
Naturally occurring inorganic solid
4
Unit of force
5
Blocking of light by a celestial body
7
Group of similar cells
9
Icy body with a tail near the sun
11
Preserved remains of ancient life
Down
2
Smallest unit of an element
3
Hottest planet in solar system
4
Center of an atom or cell
6
Particle of light
8
Gas form of a liquid
10
Form of thermal energy
12
Curved glass that refracts light