Across
1
Naturally occurring inorganic solid
5
Blocking of light by a celestial body
6
Unit of energy
7
Mass per unit volume
9
Gas essential for breathing
Down
2
Group of similar cells
3
Disturbance that transfers energy
4
Precious yellow metallic element
8
Preserved remains of ancient life
10
Reddish electrical conductor
11
Curved glass that refracts light
12
Tissue that contracts for movement