Across
1
Infectious microscopic agent
3
Gas essential for breathing
4
Particle of light
6
Basic unit of life
9
Substance with pH above 7
10
Reddish electrical conductor
Down
1
Hottest planet in solar system
2
Curved glass that refracts light
5
Mass per unit volume
7
Our home planet
8
Precious yellow metallic element
11
Form of thermal energy