Across
1
Nerve cell in the brain
4
Smallest unit of an element
5
Blocking of light by a celestial body
6
Chemical element in table salt
7
Solid with repeating atomic pattern
8
Path of a planet around the sun
9
Ball of burning gas in space
10
Basic unit of life
Down
1
Center of an atom or cell
2
Group of similar cells
3
Mass per unit volume
11
Icy body with a tail near the sun
12
Our home planet