Across
1
Blocking of light by a celestial body
3
Measure of matter in an object
5
Gas essential for breathing
6
Center of an atom or cell
7
Curved glass that refracts light
8
Glass that splits light into spectrum
Down
2
Preserved remains of ancient life
3
Naturally occurring inorganic solid
4
Mass per unit volume
5
Compound containing oxygen
9
Basic unit of life
10
Our home planet