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
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.
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.
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!
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?
@@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.
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..
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
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?
There is an another direct method to find wavelength of a photon , Taking Rydberg's constant to be 109677cm^-1 So then a different way to solve this question would be 1/wavelength = - 109677(1/6^2 - 1/3^2) = 9139.75 That implies , wavelength = 1/9139.75 = 1.0941 X 10^-6 m
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.
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 ☺️❤️❤️👍
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
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 .
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)
It will always match. The electron releases energy (it releases a photon) and drops down the exact amount that it lost👍 That's at least how I understood it after the video. Hope this helps!
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?
ah the million dollar question! so do this, check out my clips on waves and standing waves in the classical physics series. then, check out my clip on quantum mechanics in the modern physics series. then all shall be revealed!
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😢😂😂😂
Most other people take 2 hours to explain these concepts.
This is now my favorite TH-cam channel.
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!
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
Also gotta say, this episode was really Bohring.
Haha
Hahaha. Nice one
Nice one😂 but it wasn't
Dad jokes here 😂😂
lol truee
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.
Give me
this is more educative than my chemistry teacher's 45 minute lectures. thank you so much for this video!
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.
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
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
Wow!!! , even my teacher didn't explain like this. You are great Mr. Dave.... ❤ from india...
Thanks!
pov: you are here because you are studying for your chemistry final
Nope it’s only the first monthly exams for me
bro explained a 1 hour lecture in 5 minutes that's talent right there
Thank you!!! My teacher never explained even half of that.
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.
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.
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.
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!
Lord,I wish you were my teacher.Thank the lord for having someone like you PROF DAVE
ur better than my school chem teacher
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?
This comment is from India. And hey I m a student of higher class and I like your explanation style........ Ty
For my final exam,I learn a lot from you .thank you so much!!
where was this video my whole life....its got the points
In my school 2days class you explained in minutes thanks for your teaching me and my friends also subscribed this channel
Professor Dave I love you so much, you just don’t understand how clutch you are
Thanks! now I can ace my quantum mechanics exam this coming spring lol
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.
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?
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?
Greetings from Egypt Prof.Dave❤️
If it wasn't for your videos I'd never understand this subject I love so much 💕💖💜
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..
one subtopic 5 min
daily study one subtopic, in a month, covered whole semester
this is time efficiency at the peak
I promised to go through all your vdo. Clear explanation and yet have Q&A. Thanks a lot Professor.
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
You make me love chemistry...
For me those mathematical steps are tough ..but some how I make it ..now relaxed..sir thanks for the video
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.
You're my hero!
Sir, you are a great teacher.
im gonna have to start taking notes here to remember all these equations
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
LEGEND DAVE ❤️❤️❤️
The Best Explanation ever (and also well summarized)
Well he explains better than my ncert class 11 textbook thank u so much
Thank you so much Professor Dave. I am a student from India. Very well explained.
Awesome explanation
Love this guy, he's good at teaching 👍
Wow, you saved me hours in a few minutes, thank you very much ✅✅
Way better than my college professor!
There is an another direct method to find wavelength of a photon ,
Taking Rydberg's constant to be 109677cm^-1
So then a different way to solve this question would be
1/wavelength = - 109677(1/6^2 - 1/3^2) = 9139.75
That implies , wavelength = 1/9139.75 = 1.0941 X 10^-6 m
409/904
Best explanation ever
GODDAMNNN DAVE, EXPLAINED THIS COMPLEX FOREIGN CONCEPT LIKE CAKE
one of the best videos i have seen thank you
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.
You are amazing man
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 ☺️❤️❤️👍
Thanks to professor Dave is have gained alot from your teachings
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!
Thanks heaps for your concise lucid and didactic explanations, all of them. :-)
Professor Dave the chemistry Goat thank you for explaining
Thank you sir for the best explanation of bohr model
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.
why is the final answer positive if the energy is being emitted?
cirumference of electron configuration =area of atom × diameter.
What is the relationship between this hydrogen energy levels and the atom configuration of all the elements?
Thank you! ❤️
I upvote because of the lesson, and especially the cute intro.
Loved the jingle!
Oh, yeah, and the video too!
YOUR VIDEOS REALLY HELPED THANK YOU SO MUCH !
Obviously your are good. You know all about science
Underrated.
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
thank you david
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 if energy of photon doesn't match with energy gap?
It will always match. The electron releases energy (it releases a photon) and drops down the exact amount that it lost👍
That's at least how I understood it after the video. Hope this helps!
Okay.. Math playlist it is for me. 2:28 broke my brain but atleast i understood the theoretical parts.
I love this, it is really inspiring.
This guy explained more in 5 minutes than my teacher did in 30 pages and 1.5 hours of lecture
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.
you are the best professor!!
Professor Dave is a big boss
How can the energies of the other 117 elements of the periodic table be calculated?
Too good I can't explain
you're just an amazing person
Thank you
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?
its like a perfectly crafted engineering marvel similar to transisters
The last question, how do we know the speed of light since c is unknown???
Thank you so much
Excellent explanation. Thank u
Where is that -R sub H number coming from? How is that calculated?
Sir why is the potential energy of an electron quantized?
ah the million dollar question! so do this, check out my clips on waves and standing waves in the classical physics series. then, check out my clip on quantum mechanics in the modern physics series. then all shall be revealed!
THANK YOU SIR FOR APPRECIATING MY QUESTION!!!
Amazing Video
Thanks dude