Across
1
Center of an atom or cell
2
Molten rock beneath Earth surface
5
Amplified beam of light
6
Preserved remains of ancient life
10
Form of thermal energy
11
Unit of energy
12
Path of a planet around the sun
Down
2
Measure of matter in an object
3
Absolute temperature scale unit
4
Gas essential for breathing
7
Blocking of light by a celestial body
8
Naturally occurring inorganic solid
9
Substance with pH below 7