Across
1
Our home planet
3
Gas essential for breathing
6
Measure of matter in an object
8
Biological catalyst
9
Unit of force
13
Path of a planet around the sun
Down
2
Unit of heredity
4
Push or pull on an object
5
Mass per unit volume
7
Particle of light
10
Naturally occurring inorganic solid
11
Reddish electrical conductor
12
Unit of power