Across
1
Basic unit of life
2
Chemical element in table salt
3
Fourth state of matter
6
Unit of power
7
Form of thermal energy
9
Path of a planet around the sun
10
Tissue that contracts for movement
12
Curved glass that refracts light
Down
1
Element found in all living things
4
Blocking of light by a celestial body
5
Force that attracts objects together
6
Disturbance that transfers energy
8
The Red Planet
11
Our home planet