Across
1
Natural satellite of Earth
4
Substance with pH below 7
5
Measure of matter in an object
6
Biological catalyst
7
Second lightest element
Down
2
Nerve cell in the brain
3
Center of an atom or cell
8
Fourth state of matter
Natural satellite of Earth
Substance with pH below 7
Measure of matter in an object
Biological catalyst
Second lightest element
Nerve cell in the brain
Center of an atom or cell
Fourth state of matter