Across
1
Gas essential for breathing
4
Measure of matter in an object
5
Ball of burning gas in space
7
Push or pull on an object
8
Preserved remains of ancient life
Down
2
Chemical element in table salt
3
Substance with pH above 7
6
Solid with repeating atomic pattern
9
Center of an atom or cell
10
Infectious microscopic agent
11
Unit of force