Across
1
Icy body with a tail near the sun
4
Preserved remains of ancient life
6
Precious yellow metallic element
8
Second lightest element
9
Amplified beam of light
11
Nerve cell in the brain
Down
2
Tissue that contracts for movement
3
Curved glass that refracts light
5
Solid with repeating atomic pattern
7
Mass per unit volume
10
Basic unit of life