Across
1
Gas essential for breathing
5
Preserved remains of ancient life
6
Mass per unit volume
8
Icy body with a tail near the sun
10
Form of thermal energy
11
Magnetic metallic element
Down
2
Solid with repeating atomic pattern
3
Blocking of light by a celestial body
4
Unit of force
7
Particle of light
9
Tissue that contracts for movement