It's so cool that you cover every subject I'm currently studying. After every class I have, I watch your videos about it and they help me understand every detail even better
This video really helped me understand Bohr and Balmer series more...I was originally only here for Balmer and found this by mistake but I'm so glad I stayed for you to cover both models. You're brilliant! Best of luck to you and thank you, it really helped me for PChem!
My dude. I'm gonna tell you a little story. I won a scholarship to Taiwan as a military so it wasn't normal. I recieved 2 months of study for the language and then all the main courses like physics and chemistry were in chinese. You are my hero.
What?? These are two different units that you’ve presented. wtf is this. One I’d in joules which does represent energy but the other is in meter?? What??
@@90daydifferencedifferent formula different constants. The formula showen in the video is for energy. So constant is in Jules And the thing he's talking about the formula for wavelength. So constant it's in /m
This is one of the best explanations ever and the best explanation of the bohr model ever! It connected all the topics together in a short and simple way and answered all my questions!
Really it's worth .... Saving time..You told everything in minimum time..You are genius..Thank you very much for uploading and sharing your knowledge.. YOU ARE THE BEST PROFESSOR IN THE WORLD..
why at 2:28 to 2:31 does the photon energy go from a negative to a positive? Is that because the electron is said to have lost energy so the negative shows this? Where as the number for the energy must be positive?
Great video linking physics to chemistry. One thing puzzles me, though. We learned in electron configuration that each electron has its own place in a shell, subshell and orbital. What if a photon bumps an electron residing in 1s to 3p, but 3p is already full. Does the displaced electron kick one of the electrons out of 3p? And what happens to 1s that has lost an electron?
@@karhukivi Thank you. I figured it out from another video. I just found the formula in Serway's book and there was no mention about the R having different measurement units.
isn't the finally answer of the wavelength in the example negative become E = -4.08 * 10^-19 so the wavelength will be -4.86 * 10^15..... I love your explanation thank you so much for your help ☺️❤️❤️👍
3:45 gives an amazing example of the usefulness of this model. 3:50 reminds me why I hated school. Of course I ask that very comprehension question every time I look at the sky.
3:08 I play a game about exploring space, so my analogy is: Let's say you have a spacecraft orbiting at a certain distance from the center. You can raise the apoapsis however you want. To get a parabolic escape, you only need a finite amount of energy, after which you end up in a hyperbolic trajectory and have a 'speed at infinity.' Note: This is meant as an analogy and not an actual representation of what happens.
Ive been learning from this playlist in preporation for chem 1110 in college starting in January (its nov 1). I feel like I already know so much only 13 videos in. Ive only been learning for 6 days and on your 16th video with the periodic table, I see lots of people talking about their midterms. Am I really going to learn an entire college chemistry class in less than 10 days.... um hello education system get your stuff together and learn a thing or two from professor dave
Professor Dave, I think 3:00 is slightly inaccurate. The energy needed to eject an electron is indeed finite (just take the limit as n approaches infinity in the Rydberg's equation), but the distance from the nucleus to the shell that corresponds to n = infinity is infinite, as given by the Bohr's radius: r = a_0 n^2 where n is the shell number. I think you just got mixed up, great video nonetheless.
Based on my understanding in this study of Bohr model of the hydrogen atom or a hydrogen-like ion where the negatively- charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus and where an electron jumps between orbits it is accompanied by an emitted or absorbed amount of electromagnetic energy
Hello professor,, It's really incredible !! Love to see a teacher giving his best to his students.. ..And teaching with love !! Love from a learner !!!
it's not so much that: the transitions to level 2 in hydrogen "just happen to fall in the visible spectrum" as it is that: our eyes evolved to detect those transitions (i'm guessing because the transitions to level one were too hard to handle)
is there a good explanation for why the electron energy is negative? I assume we only use the absolute value when calculating the wavelength because in that case we are only looking at the change in energy (plus wavelength would be positive anyways). But what is the actual energy of the electron, and not the change in energy when it goes through a transition? I know it has something to do with that is really the energy it takes to remove the electron from the atom itself, so how do we mathematically put this together with the total energy in the system of the atom? Not entirely sure if this question makes sense.
I don't understand how you've got from the penultimate line to the last line. Surely putting in a negative value for E would give a negative value for l (although l has to be positive) as h and c are both positive?
This was really helpful. Thank you! One question: why does hydrogen have the series for n=2? Shouldn't it be n=1, since it's only got one electron? Why would it start at the second energy level?
but photons are emitted when an electron relaxes from an excited state to a lower state. it can go from 4 to 2, or 4 to 1, or 3 to 2, any transition is possible and will be accompanied by the emission of a photon of a particular wavelength that corresponds to the change in energy associated with that transition.
@@ProfessorDaveExplains Oh, so we're talking about photons being _emitted,_ not _absorbed!_ I don't know how I missed that, since I'm pretty sure you explicitly mentioned it in the video now that I think about it. 🤦 So is it just that every element has a single lowest energy level and that determines which frequencies and hence which wavelengths of light it emits? Although that still doesn't explain why hydrogen's lowest level would be 2 instead of 1. You said in your video on quantum numbers that the energy levels corresponds to the electron orbitals, yes? Hydrogen has only the single lowest orbital.
for the last exercise you made a mistake concerning the rydberg constant beacause firslty you are calculating the energy not the wave lenghth so you have to munchen there E0*Zeff V2 ,THEN AFTER when you calculate the wave lenghth you do the rydberg constant in the equation .
wouldn’t n=infinity technically be impossible because of the plank length? Because at a certain point the gap between n’s would get so small it would reach the plank length. Or am I miss understanding something?
At 1:43, you said delta E of electron = E of photon, but while doing the example (2:26) you said |delta E of electron| = E of photon. Can you or anybody else please explain the reasons for doing that way. Thanks
absolute value just makes sure there is no discrepancy in sign, since change in energy for electron can be positive or negative depending on whether absorption or emission occurs
2 hr = 5 mins
Professor Dave's equation
True AF bruh
True that
Hahaaha lol
ata ki biochemistry chanell??
Time saver; Packs a lot of information into a short time while still easy to understand.
It's so cool that you cover every subject I'm currently studying. After every class I have, I watch your videos about it and they help me understand every detail even better
Haha Same :)
He knows a lot about the science stuff!
. Good thenk
Engineering?
Good for you they pop up after I do the test😢😂😂😂
Give me
This is the only explanation of the Bohr atom I've understood. Thanks so much!
Marianne Biggs so true!🌈🌟 Thanks professor!🙏💕👑
Plz try physics wallah also ... 🙃
@@jagruti_rs by
This video really helped me understand Bohr and Balmer series more...I was originally only here for Balmer and found this by mistake but I'm so glad I stayed for you to cover both models. You're brilliant! Best of luck to you and thank you, it really helped me for PChem!
Most other people take 2 hours to explain these concepts.
This is now my favorite UA-cam channel.
I learn more from your videos than 50 minutes lecture of my college
Word pc
you study it at college and i study it at school!!
@@Syafl guess what! you will study it again in college
Manal YM 🙂💔
You study it at college but im 13 were not learning about it so I’m studying it at home. And yes i do understand everything in the Video.
@@seankrueger3848 Hey, I'm 13 too and I am learning it at home too. I actually found the concept in 'In Search of Schrödinger's Cat' by John Gribbin.
this is more educative than my chemistry teacher's 45 minute lectures. thank you so much for this video!
Also gotta say, this episode was really Bohring.
Haha
Hahaha. Nice one
Nice one😂 but it wasn't
Dad jokes here 😂😂
lol truee
Thanks!
Your entire series is incredible. Thank you so much!!
my pleasure!
It is really is. He's on my list of go to science resource recommendations.
Wow!!! , even my teacher didn't explain like this. You are great Mr. Dave.... ❤ from india...
he knows all about the science stuff
THANKS!!!!!!
Pratik Saha Lmao I always thought it was “he known alot about the science stuff”
Mr.whatever, it was his own words
My dude. I'm gonna tell you a little story. I won a scholarship to Taiwan as a military so it wasn't normal. I recieved 2 months of study for the language and then all the main courses like physics and chemistry were in chinese. You are my hero.
Value of Rydberg constant is 1.0974*10^7m.
While 2.17*10^-18J is the value for E0
so made a mistake?
What?? These are two different units that you’ve presented. wtf is this. One I’d in joules which does represent energy but the other is in meter?? What??
@@90daydifferencedifferent formula different constants.
The formula showen in the video is for energy. So constant is in Jules
And the thing he's talking about the formula for wavelength. So constant it's in /m
This is one of the best explanations ever and the best explanation of the bohr model ever! It connected all the topics together in a short and simple way and answered all my questions!
Thank you!!! My teacher never explained even half of that.
pov: you are here because you are studying for your chemistry final
Nope it’s only the first monthly exams for me
You are right men😂
I promised to go through all your vdo. Clear explanation and yet have Q&A. Thanks a lot Professor.
Really it's worth .... Saving time..You told everything in minimum time..You are genius..Thank you very much for uploading and sharing your knowledge.. YOU ARE THE BEST PROFESSOR IN THE WORLD..
If it wasn't for your videos I'd never understand this subject I love so much 💕💖💜
For my final exam,I learn a lot from you .thank you so much!!
3:54
Sir thank you so much for this. Just listening is not good enough. We need questions like that to solve to really understand.
why at 2:28 to 2:31 does the photon energy go from a negative to a positive? Is that because the electron is said to have lost energy so the negative shows this? Where as the number for the energy must be positive?
In my school 2days class you explained in minutes thanks for your teaching me and my friends also subscribed this channel
bro explained a 1 hour lecture in 5 minutes that's talent right there
Professor Dave I love you so much, you just don’t understand how clutch you are
This comment is from India. And hey I m a student of higher class and I like your explanation style........ Ty
Thank you so much Professor Dave. I am a student from India. Very well explained.
Thanks heaps for your concise lucid and didactic explanations, all of them. :-)
For me those mathematical steps are tough ..but some how I make it ..now relaxed..sir thanks for the video
The Best Explanation ever (and also well summarized)
Great video linking physics to chemistry. One thing puzzles me, though. We learned in electron configuration that each electron has its own place in a shell, subshell and orbital. What if a photon bumps an electron residing in 1s to 3p, but 3p is already full. Does the displaced electron kick one of the electrons out of 3p? And what happens to 1s that has lost an electron?
The photon will (can only?) hit the outermost electron (i.e. the highest energy level), so I don't think this is possible.
At 2:13 shouldn't the formula be 1/lamda =Rh(1/nf^2-1/ni^2)?? And the Rydberg constant is not Rh=1.097x10^7 m-1? I am so confused...
@@karhukivi Thank you. I figured it out from another video. I just found the formula in Serway's book and there was no mention about the R having different measurement units.
Greetings from Egypt Prof.Dave❤️
Thanks! now I can ace my quantum mechanics exam this coming spring lol
isn't the finally answer of the wavelength in the example negative become E = -4.08 * 10^-19 so the wavelength will be -4.86 * 10^15..... I love your explanation thank you so much for your help ☺️❤️❤️👍
3:45 gives an amazing example of the usefulness of this model.
3:50 reminds me why I hated school. Of course I ask that very comprehension question every time I look at the sky.
3:08 I play a game about exploring space, so my analogy is:
Let's say you have a spacecraft orbiting at a certain distance from the center. You can raise the apoapsis however you want. To get a parabolic escape, you only need a finite amount of energy, after which you end up in a hyperbolic trajectory and have a 'speed at infinity.'
Note: This is meant as an analogy and not an actual representation of what happens.
You make me love chemistry...
Sir, you are a great teacher.
Hi i think am missing some bit info here. If the change in energy is negative why is the wavelength positive. At what point does the sign go?
You're my hero!
Wow, you saved me hours in a few minutes, thank you very much ✅✅
LEGEND DAVE ❤️❤️❤️
ur better than my school chem teacher
Awesome explanation
where was this video my whole life....its got the points
Ive been learning from this playlist in preporation for chem 1110 in college starting in January (its nov 1). I feel like I already know so much only 13 videos in. Ive only been learning for 6 days and on your 16th video with the periodic table, I see lots of people talking about their midterms.
Am I really going to learn an entire college chemistry class in less than 10 days.... um hello education system get your stuff together and learn a thing or two from professor dave
Lord,I wish you were my teacher.Thank the lord for having someone like you PROF DAVE
Dammit!!! I feel sooo sorry for myself... I just only have 2 months for my advanced level exam... wish i found you earlier.... Your amazing sir!!
Kavindu Sureka you mean IIT?
one of the best videos i have seen thank you
Love this guy, he's good at teaching 👍
Best explanation ever
Thanks to professor Dave is have gained alot from your teachings
Thank you sir for the best explanation of bohr model
Sir, the difference btwn the energy of electrons of two orbits is given by the expression :
[(1/Ef ^2) - (1/Ei^2)]Eo = [(1/Ef ^2) - (1/Ei^2)]13.6eV
You are amazing man
Professor Dave the chemistry Goat thank you for explaining
Loved the jingle!
Oh, yeah, and the video too!
one subtopic 5 min
daily study one subtopic, in a month, covered whole semester
this is time efficiency at the peak
Thanks a lot!
So the circle of n=1 in hydrogen has a different distance between it and the nucleus then the n=1 in for example a iron atom?
correct! because they have differing numbers of protons in the nucleus.
Professor Dave Explains okay, thanks a lot!
Professor Dave, I think 3:00 is slightly inaccurate. The energy needed to eject an electron is indeed finite (just take the limit as n approaches infinity in the Rydberg's equation), but the distance from the nucleus to the shell that corresponds to n = infinity is infinite, as given by the Bohr's radius:
r = a_0 n^2
where n is the shell number. I think you just got mixed up, great video nonetheless.
No, of course the distance to n = infinity is finite, otherwise electrons could never be ejected from an atom.
Well he explains better than my ncert class 11 textbook thank u so much
Crazy how you resume 2h of a boring course to 4 mins bhoring video! Thank you so much
Thank you! ❤️
you are the best professor!!
I love this, it is really inspiring.
Finally I have understood this 🙌, thanks you 🙏☺
Excellent explanation. Thank u
I understand right now, thanks a lot Professor Dave. You're awesome!
I upvote because of the lesson, and especially the cute intro.
Based on my understanding in this study of Bohr model of the hydrogen atom or a hydrogen-like ion where the negatively- charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus and where an electron jumps between orbits it is accompanied by an emitted or absorbed amount of electromagnetic energy
more or less! the word "encircles" is a bit misleading, but other than that it's a pretty good summary.
Hello professor,, It's really incredible !!
Love to see a teacher giving his best to his students.. ..And teaching with love !!
Love from a learner !!!
Thank you so much
This was a really good explanation (and had a lot of fun facts my class didnt teach me at that!). Thank you!!
it's not so much that: the transitions to level 2 in hydrogen "just happen to fall in the visible spectrum" as it is that: our eyes evolved to detect those transitions (i'm guessing because the transitions to level one were too hard to handle)
What is the relationship between this hydrogen energy levels and the atom configuration of all the elements?
is there a good explanation for why the electron energy is negative? I assume we only use the absolute value when calculating the wavelength because in that case we are only looking at the change in energy (plus wavelength would be positive anyways). But what is the actual energy of the electron, and not the change in energy when it goes through a transition? I know it has something to do with that is really the energy it takes to remove the electron from the atom itself, so how do we mathematically put this together with the total energy in the system of the atom? Not entirely sure if this question makes sense.
Thank you very much sir
I don't understand how you've got from the penultimate line to the last line. Surely putting in a negative value for E would give a negative value for l (although l has to be positive) as h and c are both positive?
Isn't the Rydeberg constant 1.097373·10^7 m^-1 ? why is it in Joules and with another number in the video?
just a different version! they are proportional and related by planck's constant and the speed of light. used in different contexts.
Obviously your are good. You know all about science
This was really helpful. Thank you! One question: why does hydrogen have the series for n=2? Shouldn't it be n=1, since it's only got one electron? Why would it start at the second energy level?
because it becomes excited and then relaxes back down
@@ProfessorDaveExplains But wouldn't it _start_ at the lowest energy level, n=1? I thought the series for n=2 meant nᵢ=2. Is it actually n_f=2?
but photons are emitted when an electron relaxes from an excited state to a lower state. it can go from 4 to 2, or 4 to 1, or 3 to 2, any transition is possible and will be accompanied by the emission of a photon of a particular wavelength that corresponds to the change in energy associated with that transition.
@@ProfessorDaveExplains Oh, so we're talking about photons being _emitted,_ not _absorbed!_ I don't know how I missed that, since I'm pretty sure you explicitly mentioned it in the video now that I think about it. 🤦 So is it just that every element has a single lowest energy level and that determines which frequencies and hence which wavelengths of light it emits?
Although that still doesn't explain why hydrogen's lowest level would be 2 instead of 1. You said in your video on quantum numbers that the energy levels corresponds to the electron orbitals, yes? Hydrogen has only the single lowest orbital.
no the ground state is n = 1 for hydrogen and helium, if a photon is absorbed the electron goes up in energy, down if released.
for the last exercise you made a mistake concerning the rydberg constant beacause firslty you are calculating the energy not the wave lenghth so you have to munchen there E0*Zeff V2 ,THEN AFTER when you calculate the wave lenghth you do the rydberg constant in the equation .
although the final answer is true but the first step which is false
wouldn’t n=infinity technically be impossible because of the plank length? Because at a certain point the gap between n’s would get so small it would reach the plank length. Or am I miss understanding something?
thank you david
I follow you from Ethiopian country please explain more as we understand every single thing as we understand &do more examples
you're just an amazing person
Good science stuff Professor Dave!
Thank you
At 1:43, you said delta E of electron = E of photon, but while doing the example (2:26) you said |delta E of electron| = E of photon. Can you or anybody else please explain the reasons for doing that way. Thanks
absolute value just makes sure there is no discrepancy in sign, since change in energy for electron can be positive or negative depending on whether absorption or emission occurs
Thanks
why is the final answer positive if the energy is being emitted?
Excellent💯👍 thank you🌹
YOUR VIDEOS REALLY HELPED THANK YOU SO MUCH !
Love your explanations ! Thank you very much !
im gonna have to start taking notes here to remember all these equations
Too good I can't explain
Prof. Dave, thanks for the tutorials. I would like you to help me with how you had digits for the hc variables
you're the best!