Electron configurations of the 3d transition metals | AP Chemistry | Khan Academy

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[ckimsey]

Chemistry...take everything youve learned so far and throw it out everytime you wanna go further and ask "but why"...

[MR]

dude these videos are awesome! Im watching them for 2 days now and every single one of them are really helpful. Actually I have studied these subjects before in highschool but now that I am in uni I didnt remember anything! but the videos helped me to remember and also kinda master them! Thanks for the great and almost perfect tutorials

[идинахуй-кш]

2:32 isn't the 4s orbital the one with lower energy than 3d?

[g_]

Saved me within 5 minutes of the video, thank you

[robokeel]

Thanks for showing many ways to do these configurations and keeping it simple. Really helped me

[tck]

Once again thank you. Still a bit confused as to why Cr and Cu lose the s orbital but like you said, it's way too complicated for general chemistry : )

[NextGenAge]

Couldn't it be possible that the electron of Chromium could be in an intermediate state between 4s1 3d5 and 4s2 3d4. Like a resonance state that could be in equilibrium? That would make the most sense since it minimizes the energy difference of both states by being 50% in the 3d5 and 50% in the 4s2 orbit. That would also explain why it has good catalytic properties because it donates electron very easily to other molecules/atoms due its minimal grasping because of the resonance?

[leetom]

For AP Chemistry Beta, this needs a video before it explaining quantum numbers and spin bc this was so confusing out of context. I had to go searching for the explanations :(

[kachicelestine]

cool, thank you sir for the wonderful video

[karamatmohammad]

by definition 4s should be in higher energy level, but actually it has a lower energy then 3d due to its smaller distance from nucleus comparing to 3d. and (n + l) formula should be helpful in determining the order of subshell (sublevel) filling. And also by definition the valence electrons of Fe should be only 2 due to outer most energy level (4s), but Fe behaves like having up to 8 electrons in it's outer shell.

[Aditi-uqoi]

Thank you it was very confusing but now you make it easy for me 😊

[krishnathakkar]

you teach very nicely ! just love it ! a thumbs up to u

[justinaacuriouswanderer]

brilliantly explained! keep up the great work!
but i kind of have a very expected question; we've been taught that instead of saying s.. s p.. s p d.. s p d f.. they're arranged differently.. and the 1st exception actually happens to be at the transition metals, specifically scandium.. where 4s, instead of being higher energy, is actually lower than 3d (which is our first exception according to the aufbau principle)... and instead of applying this exception, we end up sticking with the regular order [indicating 4s to be higher in energy ie outermost] so why is the periodic table arranged the way it is? why doesn't the s block come first then p then d then f?

[jenf]

Hey Jay,
I really love you. Thanks a lot. I would've been in a fake thought in the rest of my days. My promise to you that one day I will learn the complicated things that you couldn't teach in the given time.

[ckimsey]

Is the oddity at Cr and Cu due to the three planar rotated d orbitals (bare with me this is difficult with only words and no pics/blackboard to draw on), referring to the xy, xz, and yz orbitals (where xy the 4 lobes lie in xy plane but are rotated 45deg. lying between the xy axis vs lying along the axis)...arent these a small energy difference from other two d orbitals?  

Being the x^2y^2 orbital (lobes lying in xy plane but oriented along each axis vs the xy orbital being 45 deg. rotation between xy axis...whew physical chemistry...) and the 5th z^2 orbital...the wierd one but ill try (2 lobes oriented along z axis similar to Pz orbital, but at center lobes are missing and a strange "doughnut" shaped lobe circles the z axis lying in xy plane and hollow in center...).

Now that the easy part is out of the way....lol...is this energy difference responsible for the stealing from 4s when theyre's 6 electrons? because the x2y2 and z2 are higher energy, to fill only one would leave a high energy orbital unoccupied so one in 4s jumps to 5th d orbital to closer balance overall energy levels...as the d's begin to fill being so 'distant' from nucleus's attraction and somewhat 'inside' 4s volume, e- repulsion pushes 4s orbital outward a bit making it even higher energy enough that it demotes an e- to last empty d orbital, which in turn drops 4s energy lvl back down and total energy of all 6 orbitals are closer together and less overall???

Thats my take on it at least

[farhanext.]

who else already thought scandium was 4s2 3d1 and surprised when he said it was weird?

[PriyaSharma-qiso]

Super trick #superchem with sonali mam

[miguelcardenas]

Great explanation, but this would make the valence electron of Cu and Mn have the same 4 quantum numbers, and that is imposible because of the Pauli exclusion principle

[barbarapagan]

CAN YOU USE BOHRS MODEL FOR TRANSITIONING METALS AND THEN TH E AUFBAU PRINCIPLE WOULD THAT MADE THE EXPLANATION EASIER?

[ButterflySimmer]

I really confused. because I been told that 4s is first and I understand it but every time I always do practice questions, they list 3D first, like some help on that.