Across
1
Biological catalyst
4
Path of a planet around the sun
6
Positive particle in nucleus
9
Second lightest element
11
Ball of burning gas in space
Down
2
Force that attracts objects together
3
Icy body with a tail near the sun
5
Molten rock beneath Earth surface
6
Tectonic landmass section
7
Substance with pH above 7
8
Mass per unit volume
10
Chemical element in table salt