Across
1
Mass per unit volume
4
Measure of matter in an object
5
Nerve cell in the brain
7
Smallest unit of an element
11
Tissue that contracts for movement
12
Molten rock beneath Earth surface
13
Form of thermal energy
14
Reddish electrical conductor
Down
2
Element found in all living things
3
Gas essential for breathing
6
Substance with pH below 7
8
Unit of force
9
Chemical element in table salt
10
Blocking of light by a celestial body