Across
1
Second lightest element
3
Element found in all living things
6
Substance with pH above 7
8
Curved glass that refracts light
9
Form of thermal energy
10
Particle of light
11
Naturally occurring inorganic solid
14
Unit of energy
Down
2
Preserved remains of ancient life
4
Push or pull on an object
5
Fourth state of matter
7
Blocking of light by a celestial body
12
Absolute temperature scale unit
13
Magnetic metallic element