Across
1
Force that attracts objects together
4
Form of thermal energy
5
Basic unit of life
7
Ball of burning gas in space
8
Disturbance that transfers energy
10
Unit of heredity
Down
2
Push or pull on an object
3
Blocking of light by a celestial body
5
Solid with repeating atomic pattern
6
Mass per unit volume
9
Curved glass that refracts light
11
Positive particle in nucleus