Exceptions to the Aufbau Principle


by smaan
Tags: aufbau, exceptions, principle
smaan
smaan is offline
#1
Dec3-12, 11:08 PM
P: 16
Are chromium and copper the only exceptions to the Aufbau Principle? If not, what are all the exceptions? Is there a list of some sort that would state all the exceptions to the Aufbau
Principle?

Thank you.
Phys.Org News Partner Chemistry news on Phys.org
First view of nature-inspired catalyst after ripping hydrogen apart provides insights for better, cheaper fuel cells
Following a protein's travel inside cells is key to improving patient monitoring, drug development
Team helps cancer treatment drugs get past their sticking point
aaku516
aaku516 is offline
#2
Dec3-12, 11:17 PM
P: 10
Upon quick examination of the periodic table, yes they seem to be the only exceptions But keep in mind this is an experimental fact and pretty much all the elements have been tested for the validity of principle for each of them, so if there were any other exceptions, they would probably been known by now! SO for now you can bank on these two exceptions without worrying about the rest, because at this point in time there dont seem to be any other ones!
DrDu
DrDu is offline
#3
Dec4-12, 02:06 AM
Sci Advisor
P: 3,378
The answer to that question depends to a large degree on the definition of the aufbau principle, i.e. on the method by which you determine the energies of the underlying atomic orbitals.

Einstein Mcfly
Einstein Mcfly is offline
#4
Dec16-12, 02:01 AM
P: 160

Exceptions to the Aufbau Principle


Try these:

How Good is the Quantum Mechanical Explanation of the Periodic Table?, Journal of Chemical Education, 75, 1384-1385, (1998)
Why the 4s Orbital Is Occupied before the 3d, Journal of Chemical Education, 73, 6, 498-503, (1996) (Co-authored with M. Melrose).

There's also an interesting article from JCE that I can't seem to find that's all about how to empirically motivate orbitals from ionization potentials. That'll also be of interest to you.
AGNuke
AGNuke is online now
#5
Dec16-12, 10:22 AM
P: 415
They (Cr and Cu) draws one electron from 4s orbital to get half filled/fully filled 3d orbital, granting them pseudo-inert configuration, thus stabilizing them. This phenomena is shown by other members of their respective groups like (Cr, Mo) and (Cu, Ag, Au).


Register to reply

Related Discussions
Why and How Does the f-block elements differ in e.config. from aufbau principle Chemistry 5
Energy levels and the Aufbau Principle Advanced Physics Homework 1
Fundamental reason behind Aufbau principle Quantum Physics 3
Questions on exceptions to Aufbau principle. . . Please help!!! Biology, Chemistry & Other Homework 1
Quine on Carnap's Aufbau General Discussion 0