Why do elements in the same group or column of the periodic table have similar properties?

A.
They have the same number of outer shell electrons.

B.
They have the same number of protons.

C.
They have the same number of electron shells.

D.
They have the same number of neutrons.

Question

Why do elements in the same group or column of the periodic table have similar properties? 	
	
 
A.
	They have the same number of outer shell electrons.
	
 
B.
	They have the same number of protons.
	
 
C.
	They have the same number of electron shells.
	
 
D.
	They have the same number of neutrons.

anonymous · Answer

They have the same number of electrons in the outer shell. This is how groups are defined.

anonymous · Answer

Thank you!!!