Across
1
Biological catalyst
2
Positive particle in nucleus
4
Chemical element in table salt
5
Magnetic metallic element
6
Icy body with a tail near the sun
8
Substance with pH above 7
9
Fourth state of matter
Down
2
Glass that splits light into spectrum
3
Second lightest element
7
Gas essential for breathing
9
Particle of light
10
Ball of burning gas in space