Across
1
Center of an atom or cell
6
Chemical element in table salt
7
Nerve cell in the brain
8
Unit of heredity
10
Second lightest element
11
Reddish electrical conductor
Down
2
Absolute temperature scale unit
3
Element found in all living things
4
Infectious microscopic agent
5
Basic unit of life
9
Unit of energy
12
Smallest unit of an element
13
Amplified beam of light