Across
1
Mass per unit volume
6
Magnetic metallic element
7
Center of an atom or cell
8
Curved glass that refracts light
9
Smallest unit of an element
12
Unit of electric potential
13
Push or pull on an object
Down
2
Chemical element in table salt
3
Tectonic landmass section
4
Ball of burning gas in space
5
Element found in all living things
10
Particle of light
11
Second lightest element