Across
1
Gas essential for breathing
4
Preserved remains of ancient life
6
Infectious microscopic agent
7
Ball of burning gas in space
9
Amplified beam of light
11
Tissue that contracts for movement
13
Natural satellite of Earth
Down
2
Push or pull on an object
3
Curved glass that refracts light
5
Absolute temperature scale unit
8
Form of thermal energy
10
Unit of energy
12
Force that attracts objects together