Across
1
Group of similar cells
4
Smallest unit of an element
6
Icy body with a tail near the sun
7
Mass per unit volume
8
Measure of matter in an object
9
Reddish electrical conductor
Down
2
Ball of burning gas in space
3
Solid with repeating atomic pattern
5
Compound containing oxygen
10
Unit of heredity
11
Unit of power
12
Unit of electric potential
13
Gas essential for breathing
14
Our home planet