Across
1
Second lightest element
3
Ball of burning gas in space
6
Push or pull on an object
7
Substance with pH above 7
9
Naturally occurring inorganic solid
10
Our home planet
11
Reddish electrical conductor
Down
2
Disturbance that transfers energy
4
Biological catalyst
5
Center of an atom or cell
6
Preserved remains of ancient life
8
Amplified beam of light
12
Smallest unit of an element