Across
1
Unit of energy
4
Solid with repeating atomic pattern
7
Absolute temperature scale unit
8
Gas essential for breathing
9
Biological catalyst
Down
2
Unit of electric potential
3
Substance with pH above 7
5
Curved glass that refracts light
6
Nerve cell in the brain
10
Icy body with a tail near the sun
11
Reddish electrical conductor