Across
1
Biological catalyst
4
Our home planet
5
Unit of energy
7
Preserved remains of ancient life
11
Naturally occurring inorganic solid
13
Particle of light
15
Curved glass that refracts light
Down
2
Mass per unit volume
3
Tectonic landmass section
6
Force that attracts objects together
8
Element found in all living things
9
Molten rock beneath Earth surface
10
Natural satellite of Earth
12
Center of an atom or cell
14
Magnetic metallic element