Across
1
Solid with repeating atomic pattern
5
Our home planet
6
Curved glass that refracts light
7
Substance with pH above 7
8
Second lightest element
11
Nerve cell in the brain
12
Absolute temperature scale unit
Down
2
Unit of energy
3
Blocking of light by a celestial body
4
Infectious microscopic agent
9
Group of similar cells
10
Magnetic metallic element
13
Particle of light