Across
1
Disturbance that transfers energy
4
Infectious microscopic agent
5
Second lightest element
7
Precious yellow metallic element
9
Ball of burning gas in space
10
Hottest planet in solar system
11
Measure of matter in an object
12
Unit of force
13
Smallest unit of an element
Down
2
The Red Planet
3
Naturally occurring inorganic solid
6
Preserved remains of ancient life
8
Chemical element in table salt