Across
1
Fourth state of matter
4
Compound containing oxygen
5
Natural satellite of Earth
7
Reddish electrical conductor
9
Substance with pH above 7
Down
2
Element found in all living things
3
Substance with pH below 7
5
Naturally occurring inorganic solid
6
Blocking of light by a celestial body
8
Second lightest element
10
Form of thermal energy