Thank you so much for this. Got my exam in an hour, this is the first time anyone's ever clearly explained these weird black lines to me.
@HypedDragon8 жыл бұрын
5:30 am revision- exams in 3 and a half hours... quality videos mate, if only I had found them sooner
@PhysicsOnline8 жыл бұрын
At least you have them now for the Depth and also for all of the year 13 content.
@HypedDragon8 жыл бұрын
+A Level Physics Online true, many thanks for the time you've took to explain the topics
@PhysicsOnline8 жыл бұрын
Good luck in your exam
@MrCoolstopmotion3 жыл бұрын
What did you get?
@bombi15913 жыл бұрын
@@MrCoolstopmotion bru that was 5 years ago
@irsyadk09108 жыл бұрын
OMG KING OF PHYSICS! thanks for this video. Exam's in a week....
@PhysicsOnline8 жыл бұрын
+necrobreen Good luck
@didierleopold8068 жыл бұрын
does the black line on the emission spectra mean that the photon emit light in all directions.
@gdr17racing51 Жыл бұрын
exams in abt 14 hours, thanks for everything man, rlly helped sum up quantum physics
@squishedmacaroni10397 жыл бұрын
I spent 3 weeks trying to understand this ........ Should have KZbin this up ...Awesome work sir
@nomchicky75158 жыл бұрын
You're such a lad
@s17034 Жыл бұрын
A level physics students 7 years on still be hating this topic
@vikiawesome33368 жыл бұрын
Each of your videos deserve at least 1 million views!! It's that good!!!
@PhysicsOnline8 жыл бұрын
+Viki awesome Thanks (I wish it does get that big!)
@jamiewhite1027 жыл бұрын
Fantastic video thank you, this helped me with my A-Levels so much!
@GiloTintin8 жыл бұрын
Got an EOT tomorrow about Quantum Physics and this just solved my confusion on Absorption Spectrums. The teachers have put up posters promoting your channel around college, absolutely class. Thank you!
@PhysicsOnline8 жыл бұрын
That is fantastic - message me with your college name and I can send some more through.
@sidra-tul-muntaha83346 жыл бұрын
I love this channel, so colorful and clear
@PhysicsOnline6 жыл бұрын
Thank you, physics shouldn't be dull!
@chriswesley5946 жыл бұрын
Wonderful stuff - thank you. On a point of grammar (because I'm an incurrable pedant) "Spectra" is the plural of "spectrum". One spectrum - several spectra.
@llinnnnds7 жыл бұрын
one of the best explanations i've seen! studying for my exam later today :)
@sanjaysojan43418 жыл бұрын
+A Level Physics Online. I love physics, I really do. If only I had you as my teacher so I could pass my exams. Thanks for the quality videos....
@PhysicsOnline8 жыл бұрын
Thanks
@majeedshah46277 жыл бұрын
Amazing! Keep it up, man!
@jawadhaider95144 жыл бұрын
There is a mistake in this video: The emission specra should have more lines than the absorption spectra, not the same amount. This is because when an electron is de-excited, it can come down in stages. i.e from n=4 to n=3, then to the ground state, with each change in energy level releasing a photon of a certain colour. So more colours are shown in the emission spectra than are blacked out in the absorption spectra.
@PhysicsOnline4 жыл бұрын
That is a very good point! You’re absolutely right, and that’s how some materials can be excited by UV radiation then emit visible light as they go back to their ground state.
@volatiledinosaur85173 жыл бұрын
Isn’t the absorption spectra all the possible paths going up? It isn’t just considering the path from ground state. It also considers n=4 to n=5 or n=2 to n=4 etc.
@Shorty503 жыл бұрын
@@volatiledinosaur8517 An excited electron will jump up energy levels. lets say from n=1 to n=3. Now to get back to n=1 it can take 2 paths. n=3 ----> n=1 or n=3 -----> n=2 ------> n=1. When they terminate at n=1 it is called the lyman series. The energy of the photon emitted when n=3 ----> n=1 will be greater than n=3 -----> n=2, because the energy difference between n=3 -----> n=1 is greater than n=3 ------> n=2. Therefore the photon will have a higher frequency.
@gowrishetty50303 жыл бұрын
isnt it possible to go up in stages as well, so why isnt it the same amount in the emission and absorption spectra
@ianmangham45703 жыл бұрын
@@Shorty50 Don't forget the fondsworth oscillation
@hafiz97119 жыл бұрын
Great videos. What I needed just 5 days before the exam :')
@nasirchaudhry672 жыл бұрын
exam in one hour thanks :)
@beechwoodproductions90876 жыл бұрын
Hi, what determines if an electron drops an energy level or stays excited. Surely, when white light is passed through a gas, and the atoms become excited, they will then de-excite right away, and emit photons of the missing wavelengths (hence no gaps in the spectra are observed)?
@jsytac2 жыл бұрын
Agreed. Can @PhysicsOnline answer this?
@AlexMoore-z6o7 ай бұрын
I know this was a long time ago, but the answer is that the photons are emitted in all directions - not just the direction that you're looking at the gas from. If the source of the white light is behind the gas, then some of that light won't carry on towards you (the observer), but instead will get emitted away from your eyes - hence darker. SOME of the light will, of course, be emitted in your direction - just not all of it.
@TENIEKEN8 жыл бұрын
omg this took alot of contemplation thank you soo muchhh mann! i gottthiss i cant believe it! thankk youu soo much for getting out your way for us!
@noahphoenix44273 жыл бұрын
This video is very useful! Thank you!
@enochbrown8178 Жыл бұрын
Outstanding!!! Thank you!!!
@silver94894 жыл бұрын
Thank you so much! This really help me understand the concept!!
@iman92433 жыл бұрын
is the emission spectra for each type of atom the same? because cant the electrons de-excite in different stages and hence produce different emission spectra? little confused there.
@joshanamalendran82017 жыл бұрын
He says that absorption spectrums occur when passing light through a cold gas, so how can it be used on stars when they release so much thermal energy?
@SM-wp5bw3 жыл бұрын
That's a very good question! The interior of the star is very hot indeed and emits white light of all wavelengths. HOWEVR, this light has to pass through the cooler outer layer of the star and also the vacuum as a result certain wavelengths are absorbed. xD hope this helps after 3 years!!
@insomniacsafterschool48696 жыл бұрын
Emission of photon when an electron moves to a lower energy level and emission of photon during gamma decay is different? During gamma decay does electron move to a lower energy level? I would appreciate it if you answer.
@mariehill65475 жыл бұрын
Also, please could you explain how a cooler gas is able to contribute to an absorption spectrum and a hotter gas is able to contribute to an emission spectrum?
@mariehill65475 жыл бұрын
Eddie Profaska Dzankic PAGY that kinda makes sense. Thanks!
@Thehopsalot8 жыл бұрын
so when an electron absorbs energy and moves up a level, wouldn't it also have to emit that level of energy as well because it's unstable there and needs to drop down? this doesn't make sense to me because that means that no matter what spectrum of light is absorbed, it must also release that spectrum of light. this doesn't make sense because then if you shine white light at something and it absorbs a certain frequency, you will still see white light reflected back because whatever was absorbed has to me emitted. sorry that was a bit confusing...
@Bugra05287 жыл бұрын
When white light passes through a material, some photons of specific frequency and of specific colour will be absorbed in the transition of an electron, whilst some photons will just pass through the material (these photons don't have that particular frequency to excite an electron). This should explain why an exact continuous spectrum of white light would not be detected on the other side of the material.
@lukejones38487 жыл бұрын
Hi, I was wondering where you cover stimulated emission (I have the year 13 videos as well) as I cant seem to find it, cheers
@TheDanieldebbarma7 жыл бұрын
do u have the explanations on Bohr's second postulate of quantisation...?if yes plz reply me the link ..I have exam tomorrow..thank you
@hammyogunlayi9 жыл бұрын
You've literally saved my life, great videos! Does this mean atoms absorb and emit the same frequency of photons?
@PhysicsOnline9 жыл бұрын
hammyogunlayi Yes, their absorbtion and emission spectra are the same (but one is like the negative image of the other).
@Mastercheif-ok6ps7 жыл бұрын
But if transitions to n=1 gives out UV, how come you say that it emits a rainbow of colours?
@mariehill65475 жыл бұрын
Are we expected to know all the energy levels in the OCR A book for a hydrogen atom? (Ground state being -13.6 to highest energy level being -0.54)?
@PhysicsOnline5 жыл бұрын
No, you don’t need to remember the exact figures.
@mariehill65475 жыл бұрын
GCSE and A Level Physics Online phew! Thank you!
@vecz48819 жыл бұрын
Great explaination :D
@bronzejourney57847 жыл бұрын
I have one question i hope you answer, helium got 2 electron, but why there more than 2 line? Is this because we cant tell where the electrons actually are? Or the matter we observe contains many atoms and data also contains things from that atoms as well? Or what? Thank you so much for the video great explanation.
@PhysicsOnline7 жыл бұрын
BronzeJourney because even for just 1 electron there are many possible energy states it could exist in.
@bronzejourney57847 жыл бұрын
Thank you and i have one more question if you dont mind, how scientist can say that galaxies going away from us by looking that spectrums, and which one they are using specificaly (I guess they are using absorbtion spectrum since stars are burning and contains gases that we can synthesize in lab, is that correct?) and why they are using that one? Thank you so much.
@PhysicsOnline7 жыл бұрын
It's the stars atmosphere that absorbs some light at these particular frequencies, when we see the star light we see what remains - and its the redshift of these lines that tells us how fast they are moving away.
@tmotu56689 жыл бұрын
Really good videos! Better than Dr PhysicsA
@emmanueloladokun539 жыл бұрын
So does that mean emission spectra is strictly when electrons move to a lower energy level and absorption spectra is strictly when electrons move to a higher energy level.
@PhysicsOnline9 жыл бұрын
You are right, the emission spectra is due to the emitted photons when electrons drop down, the absorption spectra is when the electrons move up.
@BlackSideburns8 жыл бұрын
What happens if you have light that is higher energy than needed to promote to 2 but lower than needed to promote to 3? What happens??
@PhysicsOnline8 жыл бұрын
Nothing. Only if the exact amount of energy for an electron to change levels is provided will it move. There can't be any left over.
@postmodernfishes7 жыл бұрын
Great video!!!!! Thank you
@darknessmyoldfriendhello62007 ай бұрын
exams on friday shitting myself
@avisekssarma55927 жыл бұрын
awesome video..but i have a question,,why is only some part of a colour absorbed by elements but not all part of that specific colour? i mean when some part of green colour is absorbed, why not all green colour?
@gas6733 жыл бұрын
Not all green have the same energy level all have different energy level
@DeepakSharma-pb2tz5 жыл бұрын
Very nice Explained , thanks
@numanwazir82199 жыл бұрын
when electron de excitation why it come again to lower orbit
@ElvishJumpSuit9 жыл бұрын
+numan wazir They have to........it's the Law!!! Excited states are generally short-lived and the system wants to go back to its lowest energy state. Like the way weight pulls the centre of gravity to its lowest position. Nature likes it that way ;-)
@bronzejourney57847 жыл бұрын
You cant run forever right?
@owen59073 ай бұрын
Higher physics test tmr! Cheers
@maxwilson35308 жыл бұрын
Very helpful, thank you
@ursamahan-worlds57268 жыл бұрын
Awesome!!
@samjones74633 жыл бұрын
Now this is cheeky
@lennarthanisch58044 жыл бұрын
Group 18 for ever!!!
@moleily97438 жыл бұрын
Thank you that very useful
@Tony6901019 жыл бұрын
i literally get goosebumps when i watch ur videos XD
@santoshparab34076 жыл бұрын
Thank-you sir
@harischastoukis84717 жыл бұрын
Please allow your videos in greece i am in an international school religion is not fanatic here we accept sience and your videos help me a lot thank you for your hard work please allow astophisics for us :)
@NozyNeighbor Жыл бұрын
whats 'n'?
@DeepakSharma-pb2tz5 жыл бұрын
Great
@sebacool88 жыл бұрын
For some reason we're learning this in Ireland as part of the Chemistry leaving Cert course 0.o
@PhysicsOnline8 жыл бұрын
It's all good science!
@gandhi52228 жыл бұрын
a levels physics nice with model
@akikhasan14204 жыл бұрын
nice lego models
@antowen53803 жыл бұрын
Bruh. Cheers.
@asifalamjoy95306 жыл бұрын
Sir everything is right about your videos but I would suggest you to talk a slow pace so that some of the slow learners can keep track with.
@alexwbetts7 жыл бұрын
I'm curious is everyone here in there A-levels or is there anyone younger like me ?
@PhysicsOnline7 жыл бұрын
Alex . Exe Most people are older, but that shouldn't stop you. Keep watch my and you'll find plenty of interest me material.
@ianmangham45703 жыл бұрын
Black body radiation
@jamesrobertson91496 жыл бұрын
best of luck to England football team, 2018 World Cup!
@jassvideo47272 жыл бұрын
i didn't understand anything
@lukahnapeirogon81978 жыл бұрын
Ur too quick :'(
@mariehill65475 жыл бұрын
Also, please could you explain how a cooler gas is able to contribute to an absorption spectrum and a hotter gas is able to contribute to an emission spectrum?
@qrroll1092 жыл бұрын
Cool gas has its electrons at ground state. It, therefore, doesn't emit any photons. This is why it's used for absorption spectrum and can't be used for emission spectrum. Hot gas has electrons at various energy levels. It emits various wavelengths. This is why it used for emission spectrum. If hot gas is used for absorption spectrum, it can/will absorb many for frequencies than the cold gas. I think it can still be used for absorption spectrum but it overcomplicates things. ^please correct if wrong