Across
1
Icy body with a tail near the sun
3
Blocking of light by a celestial body
4
Nerve cell in the brain
8
Unit of power
9
Magnetic metallic element
Down
1
Reddish electrical conductor
2
Group of similar cells
5
Second lightest element
6
Unit of force
7
Force that attracts objects together
10
Positive particle in nucleus
11
Element found in all living things