What is the electron configuration of the #"As"^(3-)"# ion?

1 Answer
Nov 6, 2015

Answer:

The electron configuration for the #"As"^(3-)"# ion is #["Ar"]"3d"^10"4s"^2"4p"^6"#.

Explanation:

Arsenic, As, has atomic number 33, which is the number of protons in the nuclei of its atoms. A neutral As atom would also have 33 electrons. The electron configuration of a neutral arsenic atom is #["Ar"]"3d"^10"4s"^2"4p"^3"#.

An arsenic 3- ion #("As"^(3-)")#, has gained three electrons, and its electron configuration is #["Ar"]"3d"^10"4s"^2"4p"^6"#, which is isoelectronic with the noble gas krypton, Kr.