Across
1
Path of a planet around the sun
4
Molten rock beneath Earth surface
5
Unit of power
6
Hottest planet in solar system
7
Compound containing oxygen
11
Positive particle in nucleus
13
Absolute temperature scale unit
Down
2
Smallest unit of an element
3
Unit of force
8
Substance with pH above 7
9
Nerve cell in the brain
10
Push or pull on an object
12
Unit of heredity