Across
1
Icy body with a tail near the sun
5
Form of thermal energy
6
Group of similar cells
7
Unit of energy
8
Infectious microscopic agent
10
Curved glass that refracts light
Down
2
Tissue that contracts for movement
3
Molten rock beneath Earth surface
4
Solid with repeating atomic pattern
9
Our home planet
11
Particle of light
12
Center of an atom or cell
13
Natural satellite of Earth