Across
1
Unit of energy
4
Substance with pH below 7
5
Amplified beam of light
7
Mass per unit volume
12
Hottest planet in solar system
13
Curved glass that refracts light
Down
2
Element found in all living things
3
Unit of heredity
6
Unit of electric potential
8
Molten rock beneath Earth surface
9
Unit of force
10
Magnetic metallic element
11
Center of an atom or cell
14
Compound containing oxygen