When do ionic bonds from

Question

Ionic bonds form when two atoms 

A. Exchange outer shell electrons

B. Exchange inner shell electrons

C. Share inner shell electrons

D. Share outer shell electrons

 I really don't know the answer

Answer 1

Consider the example of NaCl (i.e. common table salt).  In aqueous solution, the Na atom gives up its one outer electron, becoming the ion Na⁺, and the outer shell of the Cl atom acquires that electron, becoming the ion Cl^-.  Since Na⁺ and Cl^- have opposite electric charges, they attract and come together, forming the ionic bond of NaCl.  So you have the electron in the outer shell of Na transferring to the outer shell of Cl.  Answer (A) appears to be the best answer.