The answer is D they have 4 neutrons
I am very sure that the answer is C. Hope it’s right :)
The ion that will be formed by the selenium atom shown below when it has a stable set of valence electrons is D) Se2-.
The stability of atoms depends on whether or not their outer-most shell is filled with electrons. If the outer shell is filled, the atom is stable. ... In ionic bonds, atoms donate or receive electrons to achieve stability. In covalent bonds, atoms share electrons to achieve stability.
Thus, ionic bonds increase the stability of atoms
