Across
1
Force that attracts objects together
4
Curved glass that refracts light
5
Preserved remains of ancient life
6
Tissue that contracts for movement
7
Smallest unit of an element
10
Gas essential for breathing
Down
2
Icy body with a tail near the sun
3
Naturally occurring inorganic solid
8
The Red Planet
9
Solid with repeating atomic pattern
11
Particle of light