Across
1
Precious yellow metallic element
3
Center of an atom or cell
5
Infectious microscopic agent
6
Tectonic landmass section
8
Icy body with a tail near the sun
10
Hottest planet in solar system
Down
2
Element found in all living things
4
Biological catalyst
6
Positive particle in nucleus
7
Group of similar cells
9
Particle of light