Question

what is the result of a sodium atom transferring an electron to a chlorine atom?

Answer 1

A. The electron arrangement becomes less stable
B. The sodium atoms become more stable
c. The chlorine atoms become more stable
D. Both atoms become more stable

Answer 2

A and C are plausible choices. The ionization potential of sodium is 496 kJ/mol, and the electron affinity of chlorine is 349 kJ/mol. That is, it takes 496 kJ/mol to remove an electron from Na and you get back 349 kJ/mol when you allow it to attach to a Cl atom. So overall the system Na+ cation and Cl- anion is 496-349 = 147 kJ/mol less stable than the original Na and Cl atoms. So overall the arrangement of electrons is less stable, and, if left alone, the electron will go back to the Na atom sooner or later, so that favors A.

But on the other hand, the energy of the Cl atom is lowered by 349 kJ/mol when it forms a Cl- anion, so the chorine atom has become more stable, which favors C.

I have no idea which answer your instructor wants.

Answer 3

A. The electron arrangement becomes less stable
B. The sodium atoms become more stable
c. The chlorine atoms become more stable
D. Both atoms become more stable