Across
1
Molten rock beneath Earth surface
2
Mass per unit volume
4
Hottest planet in solar system
5
Second lightest element
Down
1
The Red Planet
3
Tissue that contracts for movement
5
Form of thermal energy
6
Ball of burning gas in space
7
Disturbance that transfers energy
8
Substance with pH below 7
9
Unit of force
10
Tectonic landmass section