Across
1
Unit of heredity
3
Force that attracts objects together
5
Measure of matter in an object
6
Curved glass that refracts light
9
Magnetic metallic element
10
Reddish electrical conductor
11
Molten rock beneath Earth surface
Down
2
Second lightest element
4
Nerve cell in the brain
7
The Red Planet
8
Blocking of light by a celestial body