Across
1
Substance with pH below 7
4
Icy body with a tail near the sun
6
Amplified beam of light
7
Form of thermal energy
9
Precious yellow metallic element
10
Glass that splits light into spectrum
Down
2
Force that attracts objects together
3
Mass per unit volume
5
Smallest unit of an element
8
Preserved remains of ancient life
11
Unit of force