Across
1
Center of an atom or cell
2
Positive particle in nucleus
6
Chemical element in table salt
7
Tissue that contracts for movement
8
Magnetic metallic element
11
Smallest unit of an element
12
Unit of electric potential
Down
2
Particle of light
3
Icy body with a tail near the sun
4
Amplified beam of light
5
Group of similar cells
9
Preserved remains of ancient life
10
Naturally occurring inorganic solid