For all but about 20 shift metals, the Aufbau diagram is a beneficial tool the helps to recognize the floor state electron construction of an element.

You are watching: What is the electron configuration of fe Iron (Fe) is a shift metal that follows the Aufbau ascendancy of the filling of atomic orbitals. The atomic number of Fe is 26, which way that its atoms contain 26 proton in your nuclei, and also if neutral, 26 electron in their electron clouds. The soil state electron construction of Fe is:

#"1s"^2"2s"^2"2p"^6"3s"^2"3p"^6"3d"^6"4s"^2"#

If girlfriend look in ~ the Aufbau diagram, you can see that the #"4s"# sublevel fills before the #"3d"# sublevel since it has actually lower energy. The electron construction lists the sublevels of each power level together, even though the #"4s"# sublevel has lower energy than the #"3d"# sublevel. Jacob T.
Mar 18, 2018

Refer to the Aufbau Principle

Explanation:

From the regular table, iron has actually atomic number #26#, definition that there space #26# electron in each ground state steel atom.

Numbers of electrons in every atomic orbital is twice the number of electron orbits in each orbital since two electron of the contrary spin occupy one orbital:#2*1=2# electron in each #s# orbital#2*3=6# electron in each #p# orbital#2*5=10# electron in each #d# orbital,and for this reason on so forth.

Electron orbitals fill according come the Aufbau (Build-up) Principle. The is, each included electrons to fill orbitals of lower energies before filling those of greater energies, so as to minimize the electrostatic potential power within the atom.

Red arrows (from peak to bottom) in the diagram listed below indicates the direction of boost in power of every orbital. The #1s# orbit is filled the first, adhered to by #2s#, #2p#, #3s#, #3p#, #4s#, #3d#, till all the #26# electrons finish up in your place.

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You could find something favor this ~ above your scrape paper.#1s=2##2s=2", "2p=6##3s=2", "3p=6", "3d=color(blue)(6)##4s=2#

Giving the electron configuration (arranged by principle energy level, e.g. #3# for #3d#)#1s^2 2s^2 2p^6 3s^2 3p^6 3d^6 4s^2#

Notice the the #4s# orbital (with principle power level #n=4#) is filled when the #3d# orbit (#n=3#) remain partly empty to acquire the most stable configuration.