Across
1
Center of an atom or cell
4
Path of a planet around the sun
7
Substance with pH below 7
8
Measure of matter in an object
10
Push or pull on an object
11
Tectonic landmass section
Down
2
Reddish electrical conductor
3
The Red Planet
5
Blocking of light by a celestial body
6
Hottest planet in solar system
9
Naturally occurring inorganic solid