determine which experiences a lower effective nuclear charge.

Question

using words and/ or drawings explain why. A) an electron in a 2s or an electron in a 2p B) a valence electron on sulfure or a valence electron on silicon C) a valence electron on chlorine or a valence electron on bromine

 

i dont get this at all! can somebody please explain this to me in details. Thank you!

Answer 1

a) For a given atom, an electron in a 2s orbital is slight closer to the nucleus than an electron in a 2p orbital, so the 2p electron experiences a lower effective nuclear charge.

b) Sulfur has 6 valence electrons, and therefore has a net effective charge of +6.  Silicon has 4 valence electrons, and therefore has a net effective charge of +4.  Sulfur and silicon are in the same period of the Periodic Table, so the valence electrons in silicon will experience the lower effective charge.

c)  Chlorine and Bromine both have a net effective charge of +7.  The valence electrons in chlorine are in principal level 3.  The valence electrons in bromine are in principal level 4, which is farther away from the nucleus.  Therefore, the valence electrons in bromine will experience the lower effective nuclear charge.