Across
1
Glass that splits light into spectrum
4
Unit of energy
6
Naturally occurring inorganic solid
8
Unit of force
11
Hottest planet in solar system
12
Force that attracts objects together
Down
2
Reddish electrical conductor
3
Magnetic metallic element
5
Biological catalyst
7
Mass per unit volume
9
Form of thermal energy
10
Path of a planet around the sun