Across
1
Measure of matter in an object
2
Basic unit of life
3
Curved glass that refracts light
5
Particle of light
8
Form of thermal energy
Down
1
Natural satellite of Earth
2
Solid with repeating atomic pattern
4
Biological catalyst
5
Fourth state of matter
6
Absolute temperature scale unit
7
Center of an atom or cell
9
Our home planet