Across
1
Smallest unit of an element
4
Hottest planet in solar system
5
Biological catalyst
8
Form of thermal energy
9
Naturally occurring inorganic solid
Down
2
Amplified beam of light
3
Icy body with a tail near the sun
4
Unit of electric potential
6
Element found in all living things
7
Nerve cell in the brain
9
Measure of matter in an object