Across
1
Biological catalyst
5
Substance with pH below 7
6
Nerve cell in the brain
7
Naturally occurring inorganic solid
8
Form of thermal energy
12
Substance with pH above 7
Down
2
Basic unit of life
3
Tissue that contracts for movement
4
Disturbance that transfers energy
6
Unit of force
9
Precious yellow metallic element
10
Force that attracts objects together
11
Group of similar cells