Across
1
Center of an atom or cell
2
Naturally occurring inorganic solid
4
Reddish electrical conductor
7
Push or pull on an object
8
Second lightest element
9
Preserved remains of ancient life
10
Disturbance that transfers energy
11
Unit of electric potential
Down
2
Measure of matter in an object
3
Amplified beam of light
4
Basic unit of life
5
Infectious microscopic agent
6
Blocking of light by a celestial body
12
Precious yellow metallic element
13
Substance with pH above 7