Elements A and X combine to form the compound A3X2. If the electron-dot symbol of the neutral atom A shows two electrons, the number of electrons in this symbol for atom X must be

2

4

5

6

 

My initial answer would have been 3 because if each A has 2, and there are three of them, there would be 6 total for A, so you need 6 total for X, so each X would need 3, but that would not an option. So I just picked 5 because 3+5=8. 5 is the right answer, but why?

 

Are you sure that the diagram is called electron-dot diagram or it is called Lewis Structure?

A₃X₂

 

I don`t understand what do you mean by the 2 electrons in the electron-dot diagram because I haven`t heard of the electron-dot diagram before.

 

Based on my speculation, I think most probably because 8 is the amount of electrons needed to achieve stability for the first stave of the electron orbits/quantum shells.

 

If possible, please tell me what is electron-dot diagram. Thanks.

Are you sure that the diagram is called electron-dot diagram or it is called Lewis Structure?

 

 

They are the same thing

Ok, so electron-dot structure is Lewis structure.

 

BTW, thanks Dr.swantson.

Edited June 25, 201411 yr by Nicholas Kang