Across
1
Measure of matter in an object
4
Natural satellite of Earth
6
Second lightest element
9
Molten rock beneath Earth surface
11
Ball of burning gas in space
Down
2
Chemical element in table salt
3
Smallest unit of an element
5
Group of similar cells
7
Infectious microscopic agent
8
Naturally occurring inorganic solid
10
Icy body with a tail near the sun