What do all elements in a column in the periodic table have in common?

Their atoms have the same number of valence electrons.
Their atoms have the same atomic mass.
Their atoms have the same number of protons and electrons.
Their atoms have the same number of neutrons.

Question

What do all elements in a column in the periodic table have in common?

 Their atoms have the same number of valence electrons.
 Their atoms have the same atomic mass.
 Their atoms have the same number of protons and electrons.
 Their atoms have the same number of neutrons.

ookawaiioo · Answer

what do you think?

rishavraj · Answer

really what do u think.....

rishavraj · Answer

can they have same number of protons???
and also no of protons = atomic no....

rishavraj · Answer

@grunge101

anonymous · Answer

oh, i'm sorry.  i just saw these.

anonymous · Answer

i think it's D, but i have no idea.  @rishavraj @oOKawaiiOo

ookawaiioo · Answer

The mass, nucleus, increase as you go right and down.  So its not D

anonymous · Answer

so A? @oOKawaiiOo

ookawaiioo · Answer

Why did you pick A?

anonymous · Answer

Because it seemed as though it was the most logical for someone who is not educated in this in the littlest amount. @oOKawaiiOo

ookawaiioo · Answer

LOL 

Valence is the number of electrons in the most outer shell...... so yes the answer is A

anonymous · Answer

oh yay! Thank you!! @oOKawaiiOo