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Electron Configuration Exceptions

Posted: Thu Oct 25, 2018 11:40 pm
by Madelyn Romberg 1H
Why do elements such as copper not follow our expected electron configurations

Re: Electron Configuration Exceptions

Posted: Thu Oct 25, 2018 11:48 pm
by LeannaPhan14BDis1D
It has something to do with the stability of the element and how it likes a specific configuration. The sublevels when they are completely filled are more stable than those that are partially filled. Sorry this is a kind of convoluted explanation but it is the only one I have. I hope more people can weigh in on this.

Re: Electron Configuration Exceptions  [ENDORSED]

Posted: Fri Oct 26, 2018 12:08 am
by Sean_Rodriguez_1J
The exceptions are slightly different for every element, but some of them revolve around prioritizing stability in the sub shells by either filling them up halfway or taking an electron from another sub shell to completely fill a sub shell. This is the case with Copper; to get a more symmetric distribution that will lead to more stability in the atom, an electron from the 4s shell in copper will move to the 3d shell so that there is a completely filled 3d orbital (why we have the 4s1d10 electron configuration). A similar rule occurs in chromium, but the shell will instead fill up 3d shell halfway (4s1d5) to maximize stability. There are more exceptions the farther up you go on the periodic table (mainly because of how small the differences in energy are between the sub shells at higher energy levels), but most of those exceptions are outside of the scope of Chem 14A.

Re: Electron Configuration Exceptions

Posted: Sun Oct 28, 2018 9:37 am
by RoopshaChatterjee 1G
What other exceptions are there to the typical electron configuration order? Is 4s always placed before 3d?