Understanding the Atom: Intro Quantum and Electron Configurations (English)

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  • Опубликовано: 16 июл 2017
  • Contents:
    Chapter 1: Protons, Neutrons, Electrons, Strong Nuclear Force, Ions, Cations, Anions, Mass Number, Atomic Mass, Atomic Number, Isotopes, Nucleus, and Relative Size of Atom, Many Examples and Calculations Worked for the Student.
    Chapter 2: Quantum Theory, Orbits vs. Orbitals, Orbital Shapes, Electron Configuration Diagram.
    Chapter 3: Writing Full Electron Configurations and Diagrams, Aufbau Rule, Hünd's Rule, Pauli Principle, and Connection between Periodic Table and Order of Filling for Electrons, Many Examples Worked for the Student.
    Chapter 4: Writing Abbreviated Electron Configurations and Diagrams, Noble Core and Valence Electrons, Many Examples Worked for the Student.
    Chapter 5: Determining the Four Quantum Numbers (Principle, Angular Momentum, Magnetic, and Spin Quantum Number), Many Examples Worked for the Student.
    Narration: William R. Sponholtz, III, B.S., M.S., PH.D.
    Full video available on RUclips Channel.

Комментарии • 579

  • @rupjyotibasumatary32
    @rupjyotibasumatary32 5 лет назад +179

    That electron cloud illustration with the camera was too good 🙇🙇🙇

    • @nicksonkosi
      @nicksonkosi 4 года назад +5

      Agreed. Cemented my understanding quite well. Wish my college quantum electronics lecturer understood this

    • @WahidKhan-mr4gx
      @WahidKhan-mr4gx 3 года назад

      Soon I will teach this to my little brother. Thanks a lot

    • @nicksonkosi
      @nicksonkosi 3 года назад

      @Dr Deuteron Actually, I think I will add concrete

    • @nicksonkosi
      @nicksonkosi 3 года назад

      @Dr Deuteron Noted Sir

    • @nicksonkosi
      @nicksonkosi 3 года назад

      @Dr Deuteron İ perfectly understand your position. However you should note that most commenters here are not professional chemists or physicists but people who interacted with this material in high school or college. TBH my lecturers/teachers never presented the material in a way that would stimulate interest or understanding. I always wondered whether she understood the topic. The video has sought to simplify (maybe oversimplified) the material using analogies anyone would understand. That's why it has gotten such positive reviews from most commenters here. While I think that your efforts at providing detail are laudable, I believe that these efforts would be more useful if directed at encouraging teachers/lecturers in schools and colleges to better teach the subject matter. If they did, we probably wouldn't be having this discussion.

  • @mizzyroro
    @mizzyroro 3 года назад +251

    I recall how I felt betrayed when after studying Thomson's plum pudding model, Rutherford's nuclear model and Bohr's orbital model in freshman high school and understanding that the electron is a particle of charge. Okay. Then we get to the senior year and we're told forget all of that an electron isn't a particle orbiting a nucleus but it is a cloud of charge surrounding the nucleus. Okay. Then I get to college and was told well its not a diffused cloud of charge but a probability of where the electron really is. 🤦‍♂️

    • @Ghryst
      @Ghryst 3 года назад +16

      the hilarious bit is, all these ppl telling you "this is how it is", and absolutely all of it is conjecture that has little evidence, none of it observational evidence, and only a single maths proof to support it.

    • @shyambhavi10
      @shyambhavi10 3 года назад +13

      U just summarised the whole thing!

    • @vvallev
      @vvallev 3 года назад +23

      And then schrödinger becomes to say “yea!!! may be is there or may be is not, to be sure don’t look at it”.

    • @nihaal7750
      @nihaal7750 3 года назад +10

      Okay this is all I want to know
      If all the previous things were wrong why did we learn them.

    • @Herearetheundead
      @Herearetheundead 3 года назад +15

      ​@@nihaal7750 Wrong is not really 100% correct either. It's just different shades of detail, some concepts are easier to understand if you use the simpler concepts of the atom. So that's why, the more you move into other subjects you will need more detailed (and more accurate) definitions of the atom for the other theory to make sense.

  • @philochristos
    @philochristos 5 лет назад +362

    I wish this had been taught to me so clearly when I was in high school and college.

    • @utetopia1620
      @utetopia1620 5 лет назад +6

      When I went to high school, the concept and understanding was different. We actually learned orbits, not orbitals, and electron position and notation wasn't as it is now.

    • @openwaters2988
      @openwaters2988 5 лет назад +8

      Hmmmm, what if the reason we can’t pin down the location of the electron is because it passes through 5 dimensional space. What we observe is the state of the electron at each snapshot in time.
      In the double slit experiment the electron takes all possible paths through to the target. We only know which path it takes if we observe it.
      What if that is why we can’t also pin down the electron orbital properly
      Our 4 dimensional world is a shadow of the 5 D world outside of ours. Just as the 2D world is a shadow of the 3D world.
      Our 4 th dimension, time, may be a shadow of the fifth dimension.
      Time itself seems one dimensional. It only goes one way, from our perspective. Top theoretical physicists say that there is no real reason why time could not flow backward.
      Maybe it does, we just can’t see, or observe it because we are one dimensional, we only observe the world in the forward arrow of time.
      An electron seems to transcend the physical,world taking al, possible paths through the two slits if not observed.
      Maybe the electron cloud,if observed properly, can give us a hint of what the fifth dimension may look like. Kind of like trying to observe a three dimensional world from the surface of a two dimensional shape.
      Just some thoughts.

    • @utetopia1620
      @utetopia1620 5 лет назад +3

      @@openwaters2988 Do a search for the "One electron universe", where theory suggests that every single electron is the same electron, that travels through space and time, to be in all places at once.
      It might go a little way to define further what you're saying.

    • @openwaters2988
      @openwaters2988 5 лет назад +1

      Utetopia yes, I’ve heard of that, couldn’t find the name of the theory though, thank you. That’s sort of what I am referring to. I will check it out.

    • @samsingh7277
      @samsingh7277 5 лет назад +1

      My school was for marks only.now I get the worst marks.

  • @manish2mech
    @manish2mech 6 лет назад +262

    Where were you!? I was looking for you all these years.

    • @jacobvandijk6525
      @jacobvandijk6525 4 года назад

      Hahahahahaha!

    • @phungoquoc7255
      @phungoquoc7255 4 года назад +1

      me too

    • @user-tn3fo3pj2x
      @user-tn3fo3pj2x 3 года назад +2

      physicist: where are you?
      electron: im at the s orbital at once, until you measured me
      einstein: you are mocking me.
      bohr: you are both alive and dead at the same time
      einstein: does the moon not exist when your not looking at it?
      physicist: ok, let's adjourn..

  • @user-ex3yt9sv8w
    @user-ex3yt9sv8w 7 месяцев назад +1

    YOU'VE SPENT 2.5MINUTES TO SOLVE ALL MY QUESTIONS ON ELECTRON SHELL,ORBITS AND SUBSHELLS.I HAVE SPENT ALMOST 4HOURS ON THIS UNTIL I'VE FOUND THIS VIDEO THANKYOU SO MUCH.This is my first time to leave a comment on RUclips thankyou so much the animation is so good

  • @kaseercreativity
    @kaseercreativity 2 года назад +29

    This channel should have views in millions........thanks to them for creating such an understandable visualisation of concepts

  • @blitzwaffe
    @blitzwaffe 5 лет назад +77

    Neither my high school nor college education on this gave me the intuition of orbitals and hybridization, but this managed to do it in 5 min. The visual alone pretty much made this so clear (camera snapshot example and combining the orbitals)

    • @bobfake3831
      @bobfake3831 3 года назад

      classic "i never payed attention and now complain"

    • @blitzwaffe
      @blitzwaffe 3 года назад +3

      @@bobfake3831 No. I slaved over lectures and office hours to try to understand hybridization. This video was the first time it simply clicked. I wouldn't blame my professors or TAs as everyone learns differently.

  • @herbburack9097
    @herbburack9097 3 года назад +33

    unbelievable lecture. waited 50 years since my college chemistry to learn all of this. Wish we had these lecturers in my time!

    • @hakinadedeji
      @hakinadedeji Год назад

      Nobody is too old to learn... trust me you will learn a lot more if you live hundred years later from now

  • @matrixate
    @matrixate 3 года назад +6

    Absolutely superb explanation, and I'm a physics major. This was so well explained. I wish, I had this explained to me when I took chemistry and quantum mechanics. Students today have no excuse for not doing well in school... None.
    The teacher will have to explain how the orbital shapes are determined though. That requires quantum mechanics, but students don't have to understand it...they just need to know that is how the shapes are determined.

  • @YH-wx3mi
    @YH-wx3mi 5 лет назад +40

    this video has to be played in every chemistry class

  • @JaiV_1d_143
    @JaiV_1d_143 24 дня назад

    AFTER TWO YEARS I FINALLY LEARNED THIS, I'M GLAD I STAYED UP LATE AND DECIDED TO LOOK UP😭 THANK YOU SO MUCHH

  • @suchitrapathak3009
    @suchitrapathak3009 6 лет назад +68

    Please upload video on Schrödinger wave equation and wave mechanics model of an atom ..

  • @anarchist28
    @anarchist28 5 лет назад +41

    I think I teared up watching this. A) Because it was so complicated yet so simple and honestly so beautiful and mindblowing. We discovered this stuff! This is the universe! I'm surrounded bt this! And B) My teacher's've been constantly and REPEATEDLY trying to explain this to me - you know all the XYZ axes & stuff but there has NEVER been a proper visual for years & I never really grasped this concept. I didn't even know electrons moved randomly.
    I can't tell you just how thankful I am. Thank you!

    • @Captain_Nemo-y7q
      @Captain_Nemo-y7q 4 года назад +4

      There were "proper visuals" years ago. I have a physics degree from 40 years ago and the non-existent visuals you refer are there in plain sight. The problem is that you didn't bother looking for them.

    • @pigeonlove
      @pigeonlove 4 года назад +1

      @@Captain_Nemo-y7q ouch

    • @nahfid2003
      @nahfid2003 4 года назад

      @@Captain_Nemo-y7q what you say is true, but still some responsibility goes yo the teacher as well.
      Instead of drawing at a board they can use a projector or smart board for animations.
      Or even print outs in class.

    • @hakinadedeji
      @hakinadedeji Год назад

      That is exactly the way to describe science... Simple and complicated. We might decide to settle for the simple or we strive on to simplify the complexiities

  • @dipakshisarma2903
    @dipakshisarma2903 4 года назад +5

    THANK YOUUU !! THANK YOU SO MUCH. MY TEACHERS AT SCHOOL TAUGHT US HOW TO WRITE THE ELECTRONIC CONFIGURATIONS FOR ANY ELEMENT WITHOUT EVEN TELLING US WHAT ARE THE BASIC "MOST IMPORTANT FACTS" BEHIND IT. WHEN I WENT THROUGH THE TOPIC IN BOOKS AND ARTICLES I TRIED TO VISUALISE IT AND YOUR VIDEO JUST MADE MY DAY !!
    THANK YOU AGAIN !
    KEEP UP THE GOOD JOB 👍

  • @mariaflorendo5153
    @mariaflorendo5153 6 лет назад +75

    Honestly one of the best videos to visualize this chapter thank you so much!

  • @matarishwan10
    @matarishwan10 7 месяцев назад

    as JEE aspirent i literally needed this thankyou for "visulization"
    thank god suggesting this even after 6 years of uploading

  • @asmaashraf5734
    @asmaashraf5734 3 года назад

    Thank You! it took me quite a while to search for how an atom would look like with al its orbitals...after being repeatedly told that atoms couldnt be visualised,has no viewable image ,needed more imagination etc and finding this video with such on point illustrations and clear explanation was really helpful.Kudos to the team 👍

  • @sanrafaa
    @sanrafaa 5 лет назад +5

    Wow... What a video !! Amazing explanation... All you need to know about Atom in under 15 mins. Thank you Sir !!!👌

  • @jasmehak3594
    @jasmehak3594 6 лет назад +16

    Thank u so much.. I had been struggling with this orbital concept for 2 months but couldn't understand the position of orbitals and sub-shells in an atom.. But your video made the concept really clear to me.. thanks once again..

    • @pigeonlove
      @pigeonlove 4 года назад

      I like your profile picture 👌😍😊🕊️

  • @thegirlnextdork
    @thegirlnextdork 2 года назад

    Seeing the electron zig-zagging around the hydrogen nucleus, and the overlapping "clouds," helped me SO much. Thank you.

  • @radhikarana5897
    @radhikarana5897 3 года назад +2

    This video is damn important for chemistry no matter how good your teacher is but the animated video help us visualise and understand this clearly......

  • @rasher939
    @rasher939 6 лет назад +25

    These videos are awesome and stupendous. Thanks for these vivid illustrations. I wonder if you could provide similar videos on why these orbitals s p d f have such peculiar shapes in 3D space. To the extent I know, these shapes are the results of three-dimensional extensions of the different modes of vibrations seen for a particle stuck in between a one-dimensional potential barrier using the time-independent schrodinger equation. But to view the creation of these 3D shapes in process from the one-dimensional and two-dimensional modes of descriptions would not be less than an amazement. I hope your efficient team would be interested in such illustrations. More or less, I find my point on the same lines of the above comment.

    • @SponholtzProductions
      @SponholtzProductions  6 лет назад +5

      Thank you for your feedback! And We will look into that topic for a future video.+Rahul Gupta

  • @vitauscas1972
    @vitauscas1972 5 лет назад +11

    This is one of the best visual representation of chemistry, Thank you.

  • @Musfiqur_anik
    @Musfiqur_anik Год назад

    This helped me a lot. Ended my 5 year long confusion. Thanks to the creator of this video and the channel

  • @AnandYadav-dc9pf
    @AnandYadav-dc9pf 5 лет назад +3

    mere doubts clear ho gaye sir. Kisi teacher ne aise nahi bataya. THANK YOU SIR

  • @swathisaravanan7440
    @swathisaravanan7440 5 лет назад +2

    This explanation was so clear and easy to understand. I was searching lot of videos to understand this topic but atlast I found. Thanks for ur beautiful explanation. upload more videos regarding chemistry

  • @swapnilsolanke3616
    @swapnilsolanke3616 6 лет назад +1

    Thanks a lot...I was looking for explanation & video like this for years...really thanks a lot...finally understood the orbitals...

  • @SamSarracino
    @SamSarracino 5 лет назад +1

    Thank you. This video makes the visualization of orbitals and electrons attainable for students.

  • @treborheminway1196
    @treborheminway1196 5 лет назад +10

    Simple and clear. I liked the Graphics of the orbitals being added together, but think it would be even better without the contast robbing background. Still very good though.

  • @gnomiefirst9201
    @gnomiefirst9201 6 лет назад +6

    Until I saw this CGI of Orbitals I was still a bit lost. The integration of CGI with an explanation really worked for me. Great learning tool!

  • @342MrIncredible
    @342MrIncredible Год назад

    got a randomly recommended... but so glad to find a channel like this... thank you for your efforts

  • @mandarpawar7015
    @mandarpawar7015 10 месяцев назад

    After all these years, I have a very clear understanding of this confusing topic.
    Very detailed video.
    Thanks. 😀

  • @ahndonh
    @ahndonh 6 лет назад +2

    best explanation of atomic structure and electron configuration

  • @rachita5644
    @rachita5644 4 года назад

    An excellent description of the making of electron cloud👍👌 Really loved it sooo much. my 4 months' doubt cleared in 5 mins! Thank you.

  • @Zafarkhan-lr7ko
    @Zafarkhan-lr7ko 5 лет назад +2

    Truly amazing explanation sir.

  • @creatorsj5359
    @creatorsj5359 10 месяцев назад

    This video has enlightened me about: atom, electrons, orbital . Thanks a lot.

  • @AshishKumar-lp4ep
    @AshishKumar-lp4ep 3 года назад +1

    I used to hate chemistry because I was unable to visualise it but this video just made me chemistry lover ❤️❤️

  • @nayanpatel1233
    @nayanpatel1233 6 лет назад +24

    very very beautiful and good explanation. thank you so much ....
    please more video.....

  • @diyamandal8328
    @diyamandal8328 Год назад

    After finding thousands of video this the only video which made me understand this ! ✨

  • @lcopeland3835
    @lcopeland3835 5 лет назад +2

    Thank you so much for this video. This video has helped me finally master this section of Chemistry

  • @Ctenomy
    @Ctenomy 5 лет назад

    Thank you!! So well I explained I finally understood not only electron configuration but the periodic table!

  • @mukamsingh3664
    @mukamsingh3664 Год назад +1

    Thank you so much sir ..
    All doubts cleared 😃😃

  • @maryj7423
    @maryj7423 Год назад

    best explanation I found so far, 3d helps so much

  • @Hiteshshlaki
    @Hiteshshlaki 3 года назад

    Oh my god...finally after so many years of studying these..I finally get a new vision to look at orbitals.

  • @minyikhamercyline2844
    @minyikhamercyline2844 3 года назад

    The explanation has been simple and clear, thank you so

  • @ramisasubah7567
    @ramisasubah7567 3 года назад

    what a video !!!!!!!!!! can not express my gratitude in words

  • @WXUZT
    @WXUZT 5 лет назад

    Clear Lucid explanation.Thank You !

  • @soumikpyne7616
    @soumikpyne7616 5 лет назад +4

    Many many many many thanks , it is really good , it is the best video to understanding the position of orbitals

  • @adityamishrxa
    @adityamishrxa Год назад

    Hats off to this video which explained such difficult concepts in such an easy way.

  • @manaalfatma8002
    @manaalfatma8002 Год назад

    This video was literally very helpful👍. Loved watching it.

  • @skotasail
    @skotasail 5 лет назад

    VERY WELL EXPOSED, ENJOYED SO MUCH LIKE TO LEARN MORE . THANK YOU SPARK!

  • @thetruthtv5018
    @thetruthtv5018 6 лет назад +92

    I. LOVE. YOU. the hard work put in this video will have eternal fruit, iloveyouiloveyouiloveyou

  • @taharaid5296
    @taharaid5296 3 года назад

    Thank u so much man ... very clear explanation ... back to back with the great representation 😁😁

  • @Ashwanikumar-qw5lv
    @Ashwanikumar-qw5lv 3 года назад +1

    Imagine how much he work hard to make this video

  • @TemplarX2
    @TemplarX2 3 года назад

    Great video. If you have to remember just one thing about the subject for life it is this:
    The orbital is a three dimensional region around the nucleus that indicates or encompasses the probable locations of an electron 90% of the time (in other words the orbital is a 90% or 0.9 probability pattern of an electron locations around a nucleus).

  • @user-zu1og7vo2n
    @user-zu1og7vo2n Год назад

    under rated video. same words as below expresses my feeling towards this video.

  • @amitpatil5151
    @amitpatil5151 5 лет назад +2

    Great Explanation Friend, Loved it.

  • @nerdgirl8029
    @nerdgirl8029 2 года назад

    The explanation and graphics are immaculate 👏

  • @harshvardhansaxena859
    @harshvardhansaxena859 Год назад +1

    Wow I am studying for JEE Advanced....after watching this I definitely have a better grasp of the concept

  • @opgamingff7764
    @opgamingff7764 4 года назад +1

    Can watch this video for million times 😍😍..........Such a nice way of explanation. Just really loved your video & expect more such videos.....

  • @Shishir27
    @Shishir27 Год назад

    The best video I've seen on this topic, thank you so much

  • @BlackElon1
    @BlackElon1 2 года назад

    THANK YOU SO MUCH!!!... this explains it SOOOO clearly ....

  • @mychaelpierce8049
    @mychaelpierce8049 2 года назад

    Great job with this video! Thanks so much for sharing!

  • @19midnightsun87
    @19midnightsun87 5 лет назад +13

    Small correction there, Aufbau is not a verb, but a noun. It can mean setup, buildup, installation, but also composition.
    The verb is "aufbauen" - "to build up"

  • @devilsgaming3666
    @devilsgaming3666 5 лет назад +1

    Best video I have cleared my all doubts thank-you 😊😊

  • @youclid2422
    @youclid2422 6 лет назад +3

    Great! Boss, Thanks a lot.

  • @alexismandelias
    @alexismandelias 5 лет назад

    Amazing detailed explanation well done!

  • @uttarakhandtour4144
    @uttarakhandtour4144 4 года назад

    Thank you👍I am gonna share this with all my mates.

  • @onanongtnongboom5598
    @onanongtnongboom5598 6 лет назад +1

    Thank you very much for your excellent video. I will share for my students

  • @muhammadaltaf9651
    @muhammadaltaf9651 5 лет назад +1

    Excellent presentation

  • @mike814031
    @mike814031 2 года назад +1

    2:42 that's really interesting, it'd be nice to hear more in-depth specifics about the complex math to calculate those orbitals...wish you'd have went into that

  • @user-yv3gz8uh1b
    @user-yv3gz8uh1b 11 месяцев назад

    a very nice lecture not only explain atomic orbitals but quantum understanding of atoms and subatomic particle

  • @rythamoberoi7523
    @rythamoberoi7523 5 лет назад +2

    Very very big thanks to u. This video is really really best to clear the concepts.

  • @vegansam364
    @vegansam364 Год назад +1

    that intro was so epic wow i am impressed!!

  • @jakisonojha8433
    @jakisonojha8433 5 лет назад +1

    So well explained.....👍

  • @malikkanaan8807
    @malikkanaan8807 6 лет назад +1

    You are awesome man
    Continue 😍😍😍

  • @rameshummati
    @rameshummati 5 лет назад +2

    amazing.just cant imagine myself having all those misconceptions about orbitals.simply enlightening

  • @XxPlayMakerxX131
    @XxPlayMakerxX131 5 лет назад +2

    I like these types of videos

  • @jakeblack8190
    @jakeblack8190 4 года назад +1

    Great video. This helped so much!

  • @SchoolTV92
    @SchoolTV92 5 лет назад +2

    very good... nice.. zabrdast

  • @sangeetha10378
    @sangeetha10378 2 года назад

    Found exactly what l wanted!!! Thank you so much sir!!

  • @suryacreation05
    @suryacreation05 5 лет назад +1

    Awesom sir...and thank for made easy in my chemistry....... From India 🇮🇳

  • @tswapna2697
    @tswapna2697 2 года назад

    thank god i understood veryyyyyyy clearly the difference between orbit and orbital. excellent explanation

  • @NotAstroXD
    @NotAstroXD 7 месяцев назад

    bro u r a legend
    cleared my doubt which had been with me since 1 year ( the reason y i hated chemistry )

  • @d.w.stratton4078
    @d.w.stratton4078 2 года назад

    The electron orbital filling overlay on the periodic table changed my life. Where the hell was this in your classroom, Mrs. Kuhar!?!?!? I got through IB Chem 1 & 2 and never saw this.

  • @luckybarrel7829
    @luckybarrel7829 3 года назад

    Great explanation! Good job!

  • @SB5SimulationsFerroviairesEEP
    @SB5SimulationsFerroviairesEEP 5 лет назад +2

    Merci beaucoup!! Thank You!! Stéph.

  • @oleron56
    @oleron56 4 года назад

    Very good. All that remains is to mention the Linus Pauling Diagram, which facilitates the distribution of electrons and is a direct consequence of this knowledge.

  • @dhr6151
    @dhr6151 3 года назад +1

    Your explanation is great

  • @whys0nalaiq420
    @whys0nalaiq420 2 года назад

    what a great effort & struggle live long SIR

  • @TheEarthandyou
    @TheEarthandyou 3 года назад

    The orbit idea was a starting place, that was improved on. It also was an instant understanding that was better than no understanding, and needs to be respected.

  • @WonderWisp_Khushbu
    @WonderWisp_Khushbu 4 года назад

    life saving video..keep up your good work..

  • @VG__
    @VG__ 3 года назад +1

    5:00🌟crystal clear...thanks a million🥺💯

  • @baburaokandunuri1840
    @baburaokandunuri1840 6 лет назад +3

    best 3D understanding ever...now clear with the idea of atom..

  • @sausagefinger8849
    @sausagefinger8849 5 лет назад

    Beautiful explanation, thank you.... every day is a school day

  • @ottomol5647
    @ottomol5647 5 лет назад

    EXCELENT VIDEO. I WOUD LIKE TO SEE ANOTHER ONE TEACHING THE ELECTRONIC BOUNDS BETWEEN ATOMS IN ORDER TO BUILD THE MOLECULES, APPLYING THE QUANTIC ORBITAL THEORY.

  • @candidopharm
    @candidopharm 6 лет назад +2

    Geeez. The best visual and explanation of orbitals I have ever received.

  • @muhammetyazmuhammedov9401
    @muhammetyazmuhammedov9401 6 месяцев назад

    This video is awesome , nice and clean explained hard topic

  • @jeanramirez8867
    @jeanramirez8867 3 года назад

    It is the best explanation that I know, it's the best atoms video

  • @jose294052
    @jose294052 5 лет назад +2

    Teachers should use your video in class, it is woderfull !