Across
1
Nerve cell in the brain
5
Amplified beam of light
6
Second lightest element
7
Smallest unit of an element
9
Biological catalyst
10
Form of thermal energy
Down
2
Naturally occurring inorganic solid
3
Gas form of a liquid
4
Hottest planet in solar system
8
Tectonic landmass section
11
Group of similar cells
12
Basic unit of life
13
Center of an atom or cell