Electron Energy Levels – A Level Physics

Published on February 23, 2015 by

GCSE Chemistry was a lie, the electrons don't just sit in their shell, they can also move about....

Thanks for watching,



Find even more videos organised by exam board and topic at:

GCSE Physics Online
► https://www.gcsephysicsonline.com
A Level Physics Online
► https://www.alevelphysicsonline.com

Your support in watching this video has been invaluable! To contribute towards the free videos on YouTube, make a small donation at:
► https://www.paypal.me/physicsonline

► https://www.youtube.com/physicsonline?sub_confirmation=1
► https://www.instagram.com/physicsonline/
► https://www.facebook.com/gcseandalevelphysicsonline

#electrons #alevelphysics #physicsonline

Category Tag


Advertise here. Telegram, Signal - Call/message +1-868-308-4028.


  • Humsy K 7 years ago

    Thankyou for such a clear video!

  • AndThatIsOwnage 7 years ago

    I really don’t understand… sorry.,

  • Ali Mohammed 7 years ago

    thank you

  • Izzy Manuel 7 years ago

    Why does each shell have a negative amount of energy? I get that the atoms become ions at the highest energy level but I don’t get why all the other shells have a negative value.

    • Physics Online 7 years ago

      +Izzy Manuel When an electron is completely removed from the atom it then has no energy (so the energy level for the outermost shell must be equal to zero). But you have to give an electron a certain amount of energy to it to raise its energy as it moves to a higher level. You keep giving it a positive amount of energy until it eventually has zero energy. That’s where the negative sign comes from. Does that make sense?

    • Izzy Manuel 7 years ago

      Oh, yes I get it, so basically you have to give the electron energy in order for it to reach zero, and when it is emitted the electron has no energy? but still has a charge?

    • Physics Online 7 years ago

      It still has a charge

    • vertonical 6 years ago

      +A Level Physics Online Basically what you are talking about is the potential energy of the electron, at the bottom of its energy well, it’s P.E is highly negative. It increases until it’s 0 at escape.

  • Sarai Kwizera 7 years ago

    makes so much sense♣

  • Albert Riber 7 years ago

    Hello, could you please explain what you mean by saying that the outermost shell is a bit like infinity? I understand that this shell represents the energy needed to create an ion, but I do not understand why it is like infinity..
    Also, would it be wrong to set the ground state of an electron (the first shell) to have 0 eV – as it is the lowest energy state it can appear in?
    Thank you for your fantastic vidoes! 🙂

  • Rinor Sylejmani 6 years ago

    What happens to an electron that has enough energy to excite to a higher energy level but also has excess energy, though not enough to excite to a further energy level- can the electron still excite to the original level or does it have to have the EXACT amount of energy equal to the energy difference in the transition levels?

    • Physics Online 6 years ago

      +Rinor Sylejmani The electron would then not be excited to the higher level. It either absorbs all the energy exactly or none at all.

    • Rinor Sylejmani 6 years ago

      Ah, ok. Thanks for the quick reply.

  • Grace Richardson 6 years ago

    is this in the year 1 mock part of the new a level syllabus? (OCR) I cant find it in the book?

    • Physics Online 6 years ago

      It was in the old spec, but for the new spec OCR exams it is now taught in year 13 alongside the astrophysics.

  • Daniyal Hassan 6 years ago

    How did you determine 13.6 eV as the lowest enegy required?

    • Physics Online 6 years ago

      +Daniyal Hassan I just used that as an example. The data like this will be provided for you in a question.

  • Samie Mohammed 6 years ago

    if your asked to draw all the possible transitions how am i meant to tell how many transitions there are

    • Physics Online 6 years ago

      +Samie Mohammed You won’t be. Often you have a simple diagram with maybe four or five energy levels and a single electron – perhaps you need to identify the smallest or largest energy change.

  • Nino Nieman 6 years ago

    I love the way you created the lego model to show that electrons must reside at a quantised energy level. It’s inspired! All your videos are really clear, and you’re a great teacher – keep them coming!

    • A Level Physics Online - Year 13 6 years ago

      +Paul Biechmann Thanks. There are analogies about balls that sit on stairs – but the limitation is that each energy level is exactly the same distance apart. Lego is great and I feel that it can really help explain some tricky concepts.

  • Siddharth Notani 6 years ago

    Hi! Can an electron absorb energy and go directly from the ground state to the energy level 0, n=infinity? or directly emit energy and pass from n=infinity to the ground state. Is that possible? or does It have to go through the other energy levels first?

    • vertonical 6 years ago

      It’s only possible theoretically if we can find a source of light that provides that much energy to it. As if stands the E.M spectrum does not.

  • David Frenkel 6 years ago

    thanks, very helpful. short and simple 🙂

  • Daniel Debbarma 6 years ago

    10/10 teaching style ..👌

    • Onim 5 years ago

      YUP, he is amazing 😀

  • Macintosh Thomas 6 years ago

    is it atom or electron which is excited or both when an atom on particular element absorbs photon energy.?

  • Esmeralda Elhamzawy 6 years ago

    a very nice video, it helped me a lot, thank uuu

  • Morgan Boyd 5 years ago

    Brilliant video – solid explanation, however if asked how many energy states there were associated with that atom, would you include the 0eV state? Since technically it is a state for the electron to exist in, but it has become delocalised and therefore not associated with that atom anymore. Been bugging me for a while now.

  • MUSHFEQUE UN NABI 5 years ago

    the Lego model for energy levels? Abso lute ly brilliant!

    • Physics Online 5 years ago

      A O M Mushfeque Un Nabi Thanks. Made sense to me.

    • JOHN M.V 3 years ago

      @Physics Online Spin of Indivisible Particle : Watch…

  • no name 5 years ago

    Are the energies for each level the energy required to raise the electron to the next level or to free it completely from the atom??

  • huntingresonance 5 years ago

    Excellent little video… really helps with follow up after lessons. Thank you!!

  • Puskar Shahi 5 years ago

    need to explain slowly mate;goin too fast(

  • LemonadePie 4 years ago

    how do you know which steps the electron can make?

  • Humza Ali 4 years ago

    How do u get -13.6

  • Saskia van Houtert 3 years ago

    Matt Anderson is somehow more to follow, but nevertheless thanks.

  • charlesumesi 3 years ago

    Brilliant tutorial! Fantastic video! Wow!

  • EN1GMA 2 years ago

    Here from Mr Tuggey

Comments are closed.