Across
1
Substance with pH above 7
4
Path of a planet around the sun
5
Compound containing oxygen
7
Tissue that contracts for movement
11
Unit of heredity
12
Natural satellite of Earth
Down
2
Unit of force
3
Amplified beam of light
6
Chemical element in table salt
8
Substance with pH below 7
9
Nerve cell in the brain
10
Curved glass that refracts light