Across
1
Unit of energy
5
Chemical element in table salt
6
Blocking of light by a celestial body
10
Group of similar cells
Down
2
Substance with pH above 7
3
Unit of force
4
Curved glass that refracts light
7
Naturally occurring inorganic solid
8
Force that attracts objects together
9
Icy body with a tail near the sun
11
Nerve cell in the brain