Across
1
Center of an atom or cell
6
Naturally occurring inorganic solid
7
Second lightest element
8
Tissue that contracts for movement
Down
2
Disturbance that transfers energy
3
Blocking of light by a celestial body
4
Hottest planet in solar system
5
Substance with pH above 7
6
Molten rock beneath Earth surface
7
Form of thermal energy
9
Chemical element in table salt