Across
1
Smallest unit of an element
4
Unit of heredity
6
Substance with pH above 7
7
Second lightest element
9
Form of thermal energy
10
Nerve cell in the brain
12
Push or pull on an object
Down
2
Our home planet
3
Element found in all living things
5
Unit of force
8
Naturally occurring inorganic solid
11
Group of similar cells