Across
1
Element found in all living things
4
Preserved remains of ancient life
6
Second lightest element
8
Icy body with a tail near the sun
11
Disturbance that transfers energy
Down
1
Basic unit of life
2
Nerve cell in the brain
3
Unit of electric potential
5
Path of a planet around the sun
7
Our home planet
9
Measure of matter in an object
10
Tissue that contracts for movement