Across
1
Element found in all living things
4
Gas essential for breathing
5
Icy body with a tail near the sun
9
Glass that splits light into spectrum
10
Unit of heredity
Down
2
Mass per unit volume
3
Unit of power
6
Reddish electrical conductor
7
Nerve cell in the brain
8
Measure of matter in an object
11
Smallest unit of an element