Across
1
Biological catalyst
4
Unit of heredity
5
Form of thermal energy
6
Path of a planet around the sun
7
Magnetic metallic element
12
The Red Planet
14
Push or pull on an object
Down
2
Mass per unit volume
3
Nerve cell in the brain
8
Unit of power
9
Gas form of a liquid
10
Force that attracts objects together
11
Particle of light
13
Second lightest element