Across
1
Mass per unit volume
4
Particle of light
7
Tectonic landmass section
8
Tissue that contracts for movement
10
Basic unit of life
Down
2
Smallest unit of an element
3
Substance with pH above 7
4
Glass that splits light into spectrum
5
Nerve cell in the brain
6
Our home planet
9
Measure of matter in an object
11
Form of thermal energy