What determines the size of an atom?

[@MrAwesomeHero1]

In the middle of rewatching his old videos and wondering when he would upload again. Ive been blessed.

[@4V3N1]

Same I was like no way I just found this channel and going through all his old shit then I see this pop up.

[@TheGoodMorty]

​​@@4V3N1lol I am rewatching for the third time at least, you are new to the channel. we are not the same (welcome, I'm just doing the meme)

[@deniztatl9992]

@@4V3N1 If not idiot, leave ASAP AND DON'T COME BACK PLS.

[@primenumberbuster404]

The king has awoken from his slumber.

[@leandrocarg]

The best physics channel is back!

[@justanotherguy469]

BAM!!!

[@wallahhabibiiii]

When the world needed him most, he came back!

[@Rudrakxh]

he returned when we needed him the most 🙌

[@VikasBhardwaj-kt8gi]

My hero has returned after one year!!! Bro i went from high school to college in the meantime...thanks for the inspiration

[@Phantomphyz]

HE HAS RISEN! Welcome back - one of the best physics channels out there.

[@alfiecattell8623]

There I was all glum, watching videos I understood. When out of nowhere came the great explainer to serenade me with another glorious video. Thank you Physics Explained!

[@ps200306]

My favourite youtube channel of all time. So good to see another video!

[@justanotherguy469]

And hear that wonderful voice!

[@novakonstant]

The return of the king! I am absolutely excited seeing a new upload from you, I have been replaying your videos every few months and now we have new content!

[@franckmalers2299]

Good to have you back !

[@jannegrey]

Yay he returned. I wondered yesterday if you will ever upload.

[@matthewbirk6575]

I stumbled upon this video and am absolutely astonished by the quality. I especially love how you went through the classical-ish intuitive answer AND the full mathematically rigorous explanation. I’d love to see a video on higher energy states! Especially how other electron orbitals lose spherical symmetry. It’s very strange to me.

[@TheGoodMorty]

I love your channel so much. PBS Spacetime makes the ideas of physics make intuitive sense, but you make the math intuitive. I love being able to follow the derivation of the Planck length, for example

[@TheGoodMorty]

I did take AP calculus and AP physics in highschool, so that helps too, but still. amazing channel and I rewatch many of them

[@josecongo9453]

We missed you. I'm glad you are back.

[@charleschidsey2831]

By far the most coherent and rigorous explanation of why atoms are stable to be found on KZbin. Even the beginning “intuitive” analysis using the Heisenberg uncertainty principle with certain assumptions is better than virtually all other explanations I’ve encountered. Hats off to you my good Sir. I shall watch this a few times until it sinks in.

[@jaw0449]

You’re back! Yay! I’m glad of the convergence

[@multicoloredwiz]

The reveal at 42 minutes... that was lovely! That was beautiful!!

[@juanvazquez1333]

No 20 minute preamble on his absence the past 3 years. Just gets straight to it 💯🙏🏼

[@vermasean]

This is really exciting!!!! I can’t wait; this is one of my favorite series & channels on the KZbins! ⚛️

[@Pixel-Pew-Pew]

Letsssss gooooo! The world has been waiting 2 years for this moment

[@63pufferfish]

The video on chandrasekhar is one of my favorites KZbin videos ever. So happy to see more.

[@valentin_5564]

That is so great you’re back

[@markonar140]

Thanks for another Interesting Physics Video!!! 👍😊

[@chrisd561]

Glad to see a new video!

[@Voron_Aggrav]

Happy to see you return, I've waited long to listen again to your wonderful videos

[@sphakamisozondi]

Oh my goodness. I cannot believe you're back. This is going to be amazing as usual 🎉

[@jpx_frd7015]

The Return of the King

[@enricolucarelli816]

Wow! What an absolute gem of clearness and knowledge! Thank you so much! 👏👏👏👏👏👏👏

[@tzaidi2349]

Thanks!

[@Kyzyl_Tuva]

Great video. Used it to help my daughter with her high school physics class. Thank you

[@KevinEuceda]

Hey!! Look who's back on KZbin! So glad you're back, I missed more of your Physics videos.

[@zephyrandboreas]

I am so glad that the creator decided to come back after such a long hiatus. It is the highest quality physics channel.

[@a.karthikraja3775]

bro u r one of the best youtubers there.U inspire me to study physics,i dont know wheather u dont have time to upload video,but i am really happy u uploaded this.

[@Vengemann]

MAN I AM SO HAPPY I THOUGHT HE WONT MAKE VIDEOS AGAIN BUT FINALYY HE MADE IT!!!

[@yinnky]

One question: the formula you presented for Heisenbergs uncertainty principle is ΔpΔx = ℏ even though the actual formula is ΔpΔx = ℏ*½, the multiplication by a half is often omitted in introductions as no actual computations are made and the intuition is still given but I don't understand why you did it here? (So the equation at the beginning wouldnt be ℏ²/(2ma²) but rather ℏ²/(8ma²)

[@asifulalamc]

Hey, great to see you back again! Your videos are superb. 😊

[@Shacthulhu]

New subscriber. Really enjoying what I am learning so far!

[@finnr3472]

THE LEGEND IS BACK

[@stephenthompson3418]

Welcome back! Love this channel!

[@curiocitizen1069]

Welcome back, the best Physics KZbinr

[@DavidAntelmo]

BRUH so GLAD YOU ARE BACK. GOATED PHYSICS CHANNEL.

[@raphaelmarquesfonseca6804]

thanks God you're back!

[@atomjack]

So excited he's back!!! Let's gooooo!

[@kalimeet___1524]

Bro you are back! Yes! good to have back the man that helped me under stand QM and Schrodinger's equation

[@GeneralTeiLing]

I really love these videos. Great work 👍

[@joek1478]

THE RETURN OF THE KING

[@justanotherguy469]

Here ye here ye, Christmas has come! I love this channel!♥

[@golammohammadkibria3247]

You came back after a long time. We're eagerly waiting for new videos. Thanks. Plz upload videos regularly.

[@JonnyMath]

I ADMIRE THIS CHANNEL SOOOO MUCH!!!!🤩🤩🤩

[@edcoad4930]

Glorious as ever. In a world going mad, physics and its beauty reassures me that I'm not going mad.

[@hrishikeshaggrawal]

Is no one going to talk about the insane fact that all bond lengths lie under less than the same order of magnitude? Like iodine iodine bonds are less than 300pm and hydrogen hydrogen bonds are 72pm.

[@trevinbeattie4888]

Since the bond length is measured from the atoms’ nuclei, I expect it to be related to the sizes of their outer shells. Paradoxically, although each shell is larger than lower ones, shells with more electrons _generally_ (but not always) are smaller than shells with fewer electrons. This sounds worth exploring further.

[@yandrak6134]

The goat is backkk

[@timelapseofdecay9028]

So then, how is it possible to have particles collide, like in particle accelerators?

[@trevinbeattie4888]

By random chance. The probability of any given particle thrown by the accelerator colliding with another is very tiny, so instead of shooting just one particle at a time they fire beams of billions of particles to increase the odds that some of them will collide.

[@timelapseofdecay9028]

@@trevinbeattie4888 But won't the uncertainty principle also apply to that, making particles with opposite charges never collide?

[@captainmeat3]

So happy to see you back

[@yusufspahi1693]

Return of the GOAT

The king has returned! Long live the king!

[@manaayek8091]

The king has returned

[@alibargh]

Loved this video! Thanks a lot ❤️❤️

[@rishikeshwagh]

The Return of The King 👑

[@thecicero92]

The return of The King

[@salvatronprime9882]

Nice to see your videos again!

[@jaimeduncan6167]

Amazing presentation.

[@drstuffy]

RETURN OF THE KING

[@spacebrain1944]

absolutely incredible video

[@ss_here_50]

Wake up guys he is back

[@thomasperkins3023]

Return of the King

[@hrperformance]

Wooohoooo! I know this is going to be superb!

[@jakenelson568]

Back w/ another banger

[@nickgonchar7272]

It's fantastic how apparently complex things appear so simple after the author's explanations!

[@petereldergill2942]

Oh. My. Crap. I'm so glad you've put out another video! I'll watch when I get home!!

[@dutonic]

MY BOI IS BACKKK!!!!

[@rudyj8948]

Oh my god HE IS BACK LETS GOOOOO we've been patiently awaiting your return!!

[@user-hu9kt3ou5v]

Yay new upload

[@backstrapped]

Oh man am I glad you are back.

[@chrischiesa609]

What makes me curious is, what causes the different shapes of the different orbitals. Why the heck would they differ?

[@c3cris2]

You’re back!!!

[@theocean6102]

He's finally back!

[@Devin-bj3wv]

Let’s gooooo he’s back

[@nickdropp5040]

I am truly blessed. missed you my friend

[@arniepatel9841]

The return of the jedi!

[@gilldeguill]

Very well explained

[@maikfidanis]

fantastic video!

[@abdirazaqali8921]

Happy new year physics legend

[@ghiath6434]

I MISSED YOU SO MUCH!!!

[@PHYSICS-l2i]

Finally he is back!

[@mgtowvalues]

ΔX and ΔP are both epistemological - that is dealing with knowledge, not with the world: as the very name "Uncertainty" Principle tells us this. The relationship between ΔX and ΔP was linked to the angular momentum of an electron bound to an atomic nucleus, which is quantized and can only be a multiple of ℏ (h-bar). This angular momentum and quantization is a physical property, not an epistemological one. Further, the statement at 4:33 of "referring to the Uncertainty Principle as "ΔX * ΔP ≈ a" is not a restatement of the Uncertainty Principle but rather a misstatement. The actual relation is "The precise relation is that the product of the uncertainty in position of a particle and the uncertainty in its momentum can never be less than one-half of the reduced Planck constant, or (ΔX * ΔP ≥ ℏ2)." Which just means that the maximum certainty is not 100% but 50%, as either 100% of momentum and 0% location, or just 50-50. This is a rather bland epistemological formulation of a somewhat tautological (necessarily true) event. I don't think I should continue with the video as the conflation of epistemological and physical and the misstatement of the relation between ℏ and the Uncertainty Principle have left a low confidence in the value of so doing.

[@LILMADERR23]

BROTHER, I love this stuff.

[@GabeKelly-p3h]

Please do not stop posting!

[@narfwhals7843]

When the world needed him most ;_; he returned!

[@BabaBabelOm]

He’s backkkkkk!!! Nice!

[@ezequielwolcan7632]

Fantastic! Thank you so much for your video. Incredible!

[@Tysonwheeler-g2i]

Holy shit he's returned to youtube.

[@madagamer233]

The master has reawakened✨

[@mettattem]

That was most epic! Thanks! 🙏

[@JPEducates]

Happy there's a new video

[@AstroBoy98]

HE'S BACK!

[@physicsboy787]

Your explanation of the question at the beginning of the video misses an important point that I think you should address. There is no problem with the fact that the potential energy causes the electron to be attracted to the proton. That is easily solved by the electron moving on a circular or elliptical orbit like a planet around a star. In fact, the potential energy of the proton and electron is identical in form to the potential energy in Newtonian gravity. And we don’t need quantum mechanics to explain why the Earth doesn’t collapse into the Sun. The real reason why we expect the electron to fall into the proton is because accelerating charges emit radiation. In order to orbit the proton, the electron must be accelerating and thus emitting radiation. But this radiation results in significant energy loss so we would expect the electron to spiral into the proton as it radiates away all of its energy. This is where quantum mechanics comes in to fix the problem, by requiring electrons to only be observed in orbits of fixed energy (known as orbitals) as you showed near the end of the video. Otherwise, great introductory explanation of quantum mechanics. Love watching your videos!

[@trevinbeattie4888]

The only flaw I see with that argument is that electrons don’t orbit around the nucleus in a circle like the Bohr model shows; according to quantum theory they exist in “probability clouds” as standing waves.

[@physicsboy787]

@trevinbeattie4888 Yes, but he stated the original problem incorrectly. At 2:38, he says that the electron must plummet into the proton because of the potential energy. This is not necessarily true.

[@qzyyyy1]

He is back!

[@sciencedoneright]

The king has returned to be seated on his throne!