Across
1
Second lightest element
4
Unit of electric potential
5
Biological catalyst
6
Smallest unit of an element
7
Particle of light
8
Magnetic metallic element
10
Gas form of a liquid
Down
1
Form of thermal energy
2
Natural satellite of Earth
3
Naturally occurring inorganic solid
6
Substance with pH below 7
9
Hottest planet in solar system
11
Path of a planet around the sun