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F-block elements

Posted: Sun Oct 28, 2018 1:12 pm
by Krisdylle Repollo 4H
I'm having trouble figuring out the electron configurations of the f-block elements. For example, the electron configuration for thorium is Rn6d^27s^2, but the atom is in the f-block of the periodic table. Why are the orbitals only d and s but not f? Is there a separate rule regarding the f-block elements of the table? Does it have something to do with their electron shells?

Re: F-block elements

Posted: Sun Oct 28, 2018 1:27 pm
by 305113590
This is because of the Aufbau principle, which basically states that the orbitals/numbers must go in numerical order in simple terms. Since Thorium is in the 5f orbital, it will not be included in the shorthand/noble electron configuration you have given.