Across
1
Tectonic landmass section
3
Unit of heredity
5
Substance with pH above 7
7
Naturally occurring inorganic solid
9
Mass per unit volume
Down
1
Positive particle in nucleus
2
Path of a planet around the sun
4
Blocking of light by a celestial body
6
Basic unit of life
8
Fourth state of matter
10
Nerve cell in the brain