横向
1
Smallest unit of an element
4
Group of similar cells
5
Magnetic metallic element
6
Ball of burning gas in space
9
Glass that splits light into spectrum
11
Unit of force
12
Tissue that contracts for movement
13
Infectious microscopic agent
14
Mass per unit volume
纵向
2
Element found in all living things
3
Unit of electric potential
7
Second lightest element
8
Measure of matter in an object
10
Center of an atom or cell