Across
1
Absolute temperature scale unit
3
Molten rock beneath Earth surface
6
Curved glass that refracts light
7
Nerve cell in the brain
8
Icy body with a tail near the sun
11
Mass per unit volume
Down
2
Second lightest element
4
Chemical element in table salt
5
Natural satellite of Earth
8
Basic unit of life
9
Unit of electric potential
10
Our home planet