Question #ee960

1 Answer
Aug 16, 2017

There are eight electrons in the antepenultimate shell of bromine.

Explanation:

Bromine has atomic number 35.

Its electron configuration is #"1s"^2color(white)(l) "2s"^2 "2p"^6color(white)(l) "3s"^2 "3p"^6color(white)(l) "4s"^2 "3d"^10 "4p"^5#.

The outermost shell (#"4s"^2 "3d"^10 "4p"^5#) contains 17 electrons.

The penultimate (almost the last) shell (#"3s"^2 "3p"^6#) contains eight electrons.

The antepenultimate (before the penultimate) shell (#"2s"^2 "2p"^6#) contains eight electrons.