fun & games & learning

[kaberett]

What I learned in this week's lecture: why atomic orbitals are referred to as s, p, d, and f (and others as appropriate): sharp, principal, diffuse and fundamental, from the series of atomic spectral lines identified in early spectroscopy.


What I relearned in this week's lecture: why (conceptually) the 4s orbital fills before the 3d orbital (because of probability density at the nucleus). Which wasn't even slightly in the lecture materials, but one of my students (there's a whole bunch of TAs, and we're each being sent off into a video conference breakout room with about five of the undergrads in breaks between chunks of lectures) asked the really good question of "is there a [comprehensible] reason for this, or do we just have to take it on trust?"

Rather to my embarrassment I had... completely forgotten the answer, and had to look it up myself, all the while knowing that I had been that student. I'm pretty sure I asked exactly that question, pretty stubbornly, until I got an answer I found satisfying, and then having got it I was happy to go on serenely accepting that that's just how the world worked, and now it's twelve or so years later and, when put on the spot, I had to go "... I'll look that up for you."

So that was dizzying.

Comments

[delight]

I remember asking a professor why spdf and never getting an answer, so thank you for clearing that up for me! Chemistry profs being difficult is basically why I didn't become a pharmacist, I think, and I feel like a lifelong mystery I had forgotten about has been answered. I could have looked it up but I'd forgotten I wanted to know.

[kareila]

Thank you for sharing that knowledge! I think most of us learn about orbitals long before we learn about spectroscopy, so I had never made the connection either!

[silveradept]

This is the way of being an academic. You could find the answer and you provided it.

[booksarelife]

Yes!!!

[cesy]

Hooray, I never understood that one either!

[catyak]

The one I always wanted to know was whether, when an electron drops from an excited state back to a lower orbital and emits a photon, there was any way to predict the direction the photon would travel, given the probability density functions of the relevant electron orbitals. I probably wouldn't understand the maths even if it was possible.