Across
1
Path of a planet around the sun
3
Element found in all living things
4
Preserved remains of ancient life
5
Form of thermal energy
8
Basic unit of life
9
Unit of heredity
Down
1
Compound containing oxygen
2
Amplified beam of light
6
Center of an atom or cell
7
Icy body with a tail near the sun
10
Smallest unit of an element
11
Unit of energy