Across
1
Solid with repeating atomic pattern
4
Fourth state of matter
5
Gas essential for breathing
6
Unit of energy
8
The Red Planet
Down
2
Mass per unit volume
3
Substance with pH above 7
7
Positive particle in nucleus
Solid with repeating atomic pattern
Fourth state of matter
Gas essential for breathing
Unit of energy
The Red Planet
Mass per unit volume
Substance with pH above 7
Positive particle in nucleus