Across
1
Absolute temperature scale unit
3
Element found in all living things
5
Mass per unit volume
9
Amplified beam of light
10
Fourth state of matter
11
Nerve cell in the brain
Down
2
Positive particle in nucleus
4
Our home planet
6
Tissue that contracts for movement
7
Unit of electric potential
8
Center of an atom or cell
12
Biological catalyst
13
Smallest unit of an element