Across
1
Magnetic metallic element
4
Our home planet
5
Naturally occurring inorganic solid
7
Mass per unit volume
8
Preserved remains of ancient life
11
Element found in all living things
12
Curved glass that refracts light
Down
2
Solid with repeating atomic pattern
3
Gas essential for breathing
5
Measure of matter in an object
6
Substance with pH above 7
9
Particle of light
10
Basic unit of life