Across
1
Substance with pH above 7
4
The Red Planet
5
Curved glass that refracts light
7
Element found in all living things
8
Unit of energy
12
Unit of force
Down
2
Ball of burning gas in space
3
Absolute temperature scale unit
6
Icy body with a tail near the sun
9
Molten rock beneath Earth surface
10
Unit of electric potential
11
Gas essential for breathing