Why can sulphur lose 6 electrons while magnesium can't gain 6?

[dontdisturbmycircles]

Hello,

I am fighting with a problem from grade 11 chem right now.

The problem is why when sulphur bonds to other atoms, its ion charge often becomes 6+ or 2- while magnesium will always form an ion of charge 2+.

I think I have an answer but am not sure. Is it because magnesium has a lower electronegativity and is less able/willing to attract extra elections? but then I have the paradox of why sulphur would be willing to lose 6(!) electrons with such a high desire to fill its last two orbitals and complete its octet (high electronegativity).

 

[Cesium]

Sulfur never loses 6 electrons to form a stable ionic compound. Sulfur can however have a +6 oxidation state in compounds such as H₂SO₄. Realize that oxidation numbers are simply part of a "bookeeping" method devised by humans to keep track of which chemical species are being oxidized and reduced. Oxidation numbers do not represent the actual charge on an atom.

With regards to ionic compounds, Mg is most stable as Mg⁺² and S as S^-2.

 

[Blueshift5]

Hello,

Thank you for bringing this question to my attention. The reason why sulphur can lose 6 electrons while magnesium cannot gain 6 is due to their electron configurations.

Sulphur has an electron configuration of [Ne]3s²3p⁴. This means that its outermost energy level, the valence shell, has 6 electrons. In order to achieve a stable octet (8 electrons in the valence shell), sulphur can either gain 2 electrons or lose 6 electrons. However, gaining 2 electrons would require a significant amount of energy, as it would have to overcome the strong repulsive forces between the electrons in the same energy level. Therefore, it is more energetically favorable for sulphur to lose 6 electrons and form a 2- ion.

On the other hand, magnesium has an electron configuration of [Ne]3s². Its valence shell only has 2 electrons, making it easier for magnesium to lose those 2 electrons and achieve a stable octet. Gaining 6 electrons would require a significant amount of energy, as it would have to overcome the strong repulsive forces between the electrons in the same energy level. This is why magnesium will always form a 2+ ion, as it is more energetically favorable.

In summary, the ability of an atom to gain or lose electrons depends on its electron configuration and the amount of energy required to do so. In the case of sulphur and magnesium, their electron configurations make it more favorable for sulphur to lose 6 electrons and for magnesium to lose 2 electrons in order to achieve a stable octet. I hope this explanation helps clarify the concept for you. Keep up the good work in your chemistry studies!