Question

What is the core notation for the electron configuration of the following particles? a. Br- : b. Na+: c. Mg : d. Al3+ :

Answer 1

Core notation is a way of showing the electron configuration of an element in terms of the inert gas core and the electrons i the outermost shell. The inert gas core can be detected by locationg the element in the peroidic table and find the inert gas at the end of the row above that partcular element.

a. In the peridic table, argon (Ar ) is inert gas at the end of the row above Bromine.

So, the core notation of Bromine (Br) is   [Ar] 3d¹⁰ 4s² 4p⁵

Therefore, the core notation of Br ^- is   [Ar] 3d¹⁰ 4s² 4p⁶ (Answer)

b. In the peridic table, helium (He ) is inert gas at the end of the row above Na⁺.

Therefore, the core notation of Na⁺ is   [He] 2s² 2p⁶  (Answer)

c. In the peridic table, neon (Ne ) is inert gas at the end of the row above Mg.

Therefore, the core notation of Mgis   [Ne] 3s²  (Answer)

d. In the peridic table, helium (He ) is inert gas at the end of the row above Al³⁺.

Therefore, the core notation of Al³⁺ is   [He] 2s² 2p⁶  (Answer)