Across
1
Nerve cell in the brain
2
Our home planet
4
Push or pull on an object
5
Icy body with a tail near the sun
8
Blocking of light by a celestial body
10
Naturally occurring inorganic solid
11
Gas essential for breathing
Down
1
Unit of force
2
Biological catalyst
3
Glass that splits light into spectrum
5
Reddish electrical conductor
6
Gas form of a liquid
7
Curved glass that refracts light
9
Unit of electric potential