A: How many unpaired electrons are there in the predicted ground state configura
ID: 864007 • Letter: A
Question
A: How many unpaired electrons are there in the predicted ground state configuration of a neutral ruthenium (Ru) atom according to the Aufbau principal?
B: What would be the predicted electron configuration for a Ni2+ ion?
C: How many unpaired electrons are there in the observed ground state configuration of a neutral ruthenium (Ru) atom?
D: Which group (column) of elements in the d-block has a different ground state distribution of electrons in the outermost s and d-orbitals for neutral atoms of each of its three elements?
E: Which elements in the d-block do NOT have the predicted electron configuration for the ground state of a neutral atom according to the Aufbau principal?
Explanation / Answer
Ru-Kr 4d75s1
unpaired electron=4
b-NI+2 - Ar4s0 3d8
c-4
d-2 nd transition series
e-many element e.g Cu in wich higher energy d orbital first before s-orbital .
Aufbau principle
According to the principle, electrons fill orbitals starting at the lowest available (possible) energy levels before filling higher levels (e.g. 1s before 2s). The number of electrons that can occupy each orbital is limited by the Pauli exclusion principle. If multiple orbitals of the same energy are available, Hund's rule states that unoccupied orbitals will be filled before occupied orbitals are reused (by electrons having different spins).