The electronic configuration of gadolinium (Atomic number 64) is?
(1) [Xe]#4f^3 5d^5 6s^2#
(2) [Xe] #4f^6 5d^2 6d^2#
(3) [Xe] #4f^8 5d^9 6s^2#
(4) [Xe] #4f^7 5d^1 6s^2#
(1) [Xe]
(2) [Xe]
(3) [Xe]
(4) [Xe]
1 Answer
Nov 17, 2017
Explanation:
This one has two "tricky" parts to it. First, the order of filling by energy level means that the d and f orbitals are not filled strictly in order of level. Second, Hund's Rule says that the most stable configuration has more single electrons, if possible.
Thus 1) doesn't even have sufficient electrons. 3) has too many. Between 2) and 4), Hund's Rule selects 4).
