Across
1
Unit of energy
3
Nerve cell in the brain
4
Chemical element in table salt
7
Unit of electric potential
11
Unit of power
12
Unit of heredity
13
Second lightest element
Down
2
Path of a planet around the sun
3
Center of an atom or cell
5
Glass that splits light into spectrum
6
Measure of matter in an object
8
Unit of force
9
Icy body with a tail near the sun
10
Compound containing oxygen