Across
1
Gas essential for breathing
4
Gas form of a liquid
5
Substance with pH above 7
7
Unit of electric potential
8
Basic unit of life
11
Naturally occurring inorganic solid
Down
2
Molten rock beneath Earth surface
3
Unit of energy
4
Hottest planet in solar system
6
Blocking of light by a celestial body
9
Unit of power
10
Positive particle in nucleus