Across
1
Smallest unit of an element
3
Unit of energy
5
Hottest planet in solar system
6
Amplified beam of light
7
Fourth state of matter
8
Nerve cell in the brain
12
Absolute temperature scale unit
Down
2
Mass per unit volume
4
Naturally occurring inorganic solid
7
Positive particle in nucleus
9
Precious yellow metallic element
10
Icy body with a tail near the sun
11
Substance with pH above 7