This video makes me realize how severely important it is to just *show* students how something works through practical explanation, and not just theoretical
I've Learnt That photoelectric effect is the phenomenon when photons with sufficient frequency hits certain metals electrons get ejected, never really visualized it :sob:
The extra bit with the positively charged plate is a really good addition to this video!! This polarity-dependent aspect of the photoelectric effect is not normally mentioned in physics books.
It’s because he only removed electrons and the positive charge is a hole. He said you couldn’t knock it off because it’s too big but in reality there is nothing there. There is a hole there look for an electron is all.
@@christopherlocke9616- Of course there is a low probability of moving the actual positive particles. Not only are they massive, but they tend to be bound to many other atoms in the solid material. BUT, that still leaves the positive pseudo-particle "holes" as you say, and they CAN migrate to some extent, plus there are the surface charges in adsorbed molecules, particularly water molecules, which tend to coat most things in layers up to hundreds of molecules thick. So indeed, _some_ positive charges can be scraped off and moved around. But the main thing moved around is the negative charges, which predominate the action and the _net effects._
which is stupid because people need to realize that light can behave like a physical object, it's an easy concept to demonstrate multiple different particles and their physics effectively
Basically light acts like partials and waves at the same time. Light isn't actually partials or waves, just acts like it in certain places. We call these "partials" photons If the light has enough energy, it can actually knock partials off of objects. Think of it as a bowl of ping pong balls. If you blow hard enough they'll reach the top of the bowl and be able to escape. The more you blow, the balls will fly out at higher speeds. However if you don't blow enough they won't escape. Now think of electrons as the ping pong balls. Add tennis balls as protons. Now you can see you'll have to blow much harder to knock the tennis balls out of the bowl compared to the ping pong balls. This is because protons are much bigger than electrons and require more energy to fling out. At least that's what I remember from highschool physics class
@@moothu So light is a shooty shooty bullet that, if it’s a high enough caliber, will deal damage to the target, but it’s also the song Big Iron (metaphorically, since the sound is in waves)
@@iakinose You either add or remove electrons to induce negative or positive charge, in no instance do you add or remove protons. It's only about electrons.
@@tohaason He said you couldn’t remove protons? So where else was the mistake, I understand it’s worded in a way to sound more possible than it is? I’m not an expert, but I have read a few textbooks in my time. However, I’m not sure of any specific mistakes he made. If he did I’d like to hear them.
the flash light was unable to remove electrons because kinetic energy is independent of the intensity of light , it only depends on frequency of light i.e einsteins photoelectric equations : KE = hf - hf0 however the UV light have enough frequency (f >threshold frequency) thus it knock off the electrons. **ncert class 12 wave optics** :)
Thank you, your the reason I came to the comments because the explanation as to white the flashlight 🔦 did not knock off electrons was due to low frequency (higher wavelength, less energy)
The comments do it for me! I didn't realize so many people son't understand what's happening. I think his last sentence could've been more precise, actually. It's more of "light has particle-like properties." Love this guy's demonstrations, but I get nitpicky about his explanations. Science communication is hard.
I understand PEE but couldn't understand his explanation bcz of his accent.... I can only understand INDIAN accent. But it feels great for me to explain such things through practical visuals.
Clarification: You're not CHARGING it with positive charges. You're scraping away ELECTRONS from the scope, thus making it positively charged. And because there are less electrons on the scope than it was normally, photons can't knock electrons off the scope, because there isn't any or enough!
In solid state physics, free charge carriers like electrons in the conduction band or holes in the valence band are considered considered particles, so a "hole where an electron should be" is considered a positive charge. You might think it's semantics, but holes are "quasi-particles" that represent positive divergences in the electric field, which is the definition of positive charge (Gauss's law), so it's not just silly word games.
@@tingtang9302 Word games can't explain why boron-doped silicon conducts electricity but pure silicon doesn't, despite the fact that neither have free electrons that could be knocked off using photons.
If you didn’t get it: basically what he’s saying is, if light only acted as a wave then a light source of any wavelength should have enough strength to remove the charge from the plate, providing the light has a high enough intensity (enough lumens). This is because the energy of waves can be additive, meaning all the photons would add their energy together to provide the amount of energy needed to remove the charge. Because light also acts like a particle, the ability for light to remove the charge is actually dependent on the wavelength of the light (which is the same thing as saying that it is dependent on the energy of the light particle). In this sense, the energy of the photons is not additive, so each photon needs to have enough energy individually to remove the charge. This is why the visible light at a high intensity couldn’t remove the charge but the UVC light (which has a shorter wavelength) could, even at a lower intensity. Hopefully someone sorts by new and sees this lol
@@Gin-kz5ss appreciate that, lol I forgot that I had even left this comment. It’s honestly still difficult to understand even in simple terms but I am glad that helped!
Just a detail: if light was a wave only, even for the right frequencies, it would take a couple of minutes for an electron to gather enough energy, from the wave, and jump out. But, as we see in the video, the effect is instantaneous.
@@14xx07yes. his general theory of relativity wasn't very well accepted cuz it was hard to prove. We proved time dilation after his death. Black holes and gravity waves were discovered fairly recently. And his theory still has a lot of elements to prove, like presence of white holes and some stuff with charged particles
@@Person-lk1vs nah he just didn't make it super clear that the dimmer light had a higher frequency. So higher energy per photon, even though there are way fewer protons. But the number of photons doesn't matter, cuz only an individual photon can knock off an electron
My guess is that usually they are slowly broken down by the administration of the school alongside the parents, throw in bad pay in most districts and you have a perfect storm for disaffected teachers. I was lucky enough to have a handful of good teachers but unfortunately I was dumb about my priorities when I was that age
I'd suggest that it's probably not that big of a factor. What really matters is is how previous generations had very little awareness that raising kids is a whole other science(not literally), so it's common for many to not have that studying attitude, a crave for knowledge. However, it is changeable if you understand your past better, what made you the way you are in terms of studying and then come up with a strategy on how you can change it. *works with other things as well
@@kanagarajponnappan9595 Pretend I pay you for your time like a job but only when you are actually working. Just for this example since you asked me to explain. If you take 1 minute to do something I'm only paying you for that one minute. If you take an hour to do the same thing then you are now getting paid for that entire hour. Clear enough? Sorry if that is more of an english language colloquialism. Good day.
Imagine being an middle/high school kid having access to educational video like this, I wish this was possible when I was in middle school, I would have definitely had better score.
I am in this exact situation and i am making the most of it, currently studying math way above my level and understanding it thanks to incredible videos and sites
Currently sophomore year of highschool and love watching vids from this guy, kursgesagt, and others like it, and I can always wrap my head around the vids, but this one just made me audibly say wtf and I'm about to rewatxh it for a 6th time to try to understand
Fun fact: when the plate is charged positive, the light actually kicks electrons out, but they're getting back into it because of the electric force (the plate already has less electrons and "pulls" the kicked out ones back)
@@aathi2255 That's what it would mean if the top of the conduction band of the metal is not within range of hv (energy) of the UV light to cause ionization. The top of the conduction band are the electrons that require the least amount of energy to be removed from the metal by the light. If the plate is charged positively enough - if enough electrons have been removed - then the gap between the top of the conduction band and the vacuum level will be larger than the energy of the UV light, and no electrons will be removed. This is a different mechanism than saying the electrons are ejected and then return due to positive charge on the plate. To be clear I don't know which one is happening! Just asking do we have evidence for one mechanism over the other.
I have been studying photonics as part of my work as a manufacturing technician in a fiber optic company. Your videos are a great way of showing these effects in an understandable way.
No kidding, 50% of what this guy says in his videos is incorrect. I swear he spends 5 minutes browsing a wiki page and then buys some cheap thing on Amazon and makes a video without double-checking anything he's researched or even bothering to understand how the physics of this actually works
For anyone having trouble understanding: Photons interact with electrons, and even though photons have zero mass (which is why they can travel the speed of light). They can still knock the electrons off the plate with enough ENERGY since electrons have such little mass to begin with (10^-28 grams). How do we know the photon’s energy? The bigger the wave, the less the energy. Radio waves are as tall as buildings but have very little energy, UV rays are smaller than the pin of a needle but they have way more energy because the wave is more sporadic, like molecules in boiling water. That’s why the regular light couldn’t knock over the electrons but the UVC light could. Protons are much heavier than electrons though (10^-24 grams) which is why the UVC light couldn’t knock them over.
I think the problem with a positive charge is not that it can't knock the protons off since they're too big, but that when the plate is charged positively all electrons go away and the the UVC light cannot put back electrons in
The "all" isn't likely. I expect the positive charge of the plate pulls back any electrons the UV light has knocked out of place. There's nothing else around to attract them, such as a plastic rod with a big positive charge, like was used to induce the positive charge on the device.
@@blairhoughton7918 I see where my words got wrong, I didn't mean to say 'all' electrons are gone. Whenever an object is charged positively, the free electrons are removed, this causes a positive charge, thus, the UVC radiation couldn't bring back the missing electrons, thus it couldn't restore a neutral charge.
@@vihangdalal Some of the free electrons in the metal electroscope are removed, but looking at the indicator it's not close to as charged as it can indicate, which, trust me, isn't nearly as charged as it can get. Even then the UV photons may be acting on bound electrons in the metal atoms not free ones in the conduction band. So the only thing keeping the electroscope from being charged more is the electrons being pulled back because it's the only sink in town.
I wish my school would teach me photoelectric effect like this, i spent 1 week straight just solving questions and numericals on it and i just now got the concept because of your video.
Public schooling is designed to discourage, even ridiculule learning on your own, in about half of nations. This allows for easier insertion of indoctrination and imperialistic propaganda. In is unfortunate, but I believe you may reside in one of those nations. The nations that are not part of the 10 most free nations on the planet are infamous for this. About 65% are guilty of this.
Except, he was wrong. Protons do NOT accumulate like indicated ... that was instead a depletion of electrons, a deficit if you will of electrons, making the charge appear positive.
@@uploadJ He didn't say protons were accumulating. He said that electrons were being removed. He implied that protons would have to be knocked off to discharge it since the photons can't add electrons.
@@facemash re: "He implied that protons would have to be knocked off to discharge" Hence, an implication they were accumulating. You don't see that? If you don't you don't, but some of us do see that.
@@uploadJ "Hence, an implication they were accumulating" No. That is not an implication of what he said. That is something you incorrectly assumed based on what he said. No one else seems to have misunderstood him. Only you.
I wish we'd stop teaching it that way. It just puts people into a mental hole that proper particle models have to work doubly hard to get them out of. All the wave theory does is show how even complicated explanations that fit some of the data are sometimes simply wrong.
Well yes but no. You can't take electrons from your hair and deposit them elsewhere.... Apart from this detail (no need to enter in deeper on orbitals and valence) yeah!
Beautiful demonstration. I have finally understood how photoelectric effect works. The reason no deflection occurs in the first case is that the brightness of light depends on the number of photons whereas the ability to knock off the electrons depends on the frequency of the photon which determines the energy of a single photon. So even though the light is bright but is emitted at a lower frequency it cannot affect the metal plate however a dimmer light emitted at a higher frequency exceeds the threshold frequency and helps knock off the electrons.
in india, photoelectric effect is taught us in 11th standard in chapter atomic structure and actually one of the easiest chapter i follow you because i get the practical approach of my concept thus enhancing my concept thank you!
Wonderful. The way you demonstrate the Laws of Photo Electric Effect is simply amazing. I've studied (memorized) for getting marks but this is the first time I see it demonstrated.
Photons carry energy that can be absorbed to eject electrons from metals creating "photoelectrons". Different materials have a different work function. The work function is the minimum energy needed to eject electrons, so if the work function energy is met, an electron is ejected, as simple as that. In modern times we've come to utilize this effect into more practical things. The photovoltaic effect is the same effect but the electrons aren't ejected, allowing for a much wider spectrum of applications.
Slight correction, the light doesn't need enough energy to knock off protons in the case of the positively charged plate. It just needs enough energy to take away electrons from the plate that already "needs" more electrons. In short the energy should be enough to overcome the binding energy of an electron on a positively charged plate which is higher in magnitude than that on a negatively charged plate.
Came here to say this. If he used an ionizing "light" it would be again slightly different. X-rays, in sufficient quantity should be able to positively charge this.
The fact that a man was riding on a train looking out the window and figured out a secret to the universe is one of the biggest W’s this worlds ever seen
Metaphorically: the low hanging fruit is gone. More scientifically: it is only certain electrons that are easily knocked loose by photons, in the outermost layers of atoms. The remaining electrons require significantly more energy per photon to knock them loose. You'd need gamma rays instead of UV rays to eject those electrons.
With only Bachelor's degree, I can choose laser enginner, PCB/semiconductor/automobile manufacturing process enginner. But being a middle school physics teacher is much more common. @@jm2340
@@_FrankMatthews_ THANK YOU! lol (I rewatched this shirt half a dozen times trying to tease out the little details I was missing). I can return to being productive again!
@@Raytracer111 this comment feels like it has the character of some sort of conspiratorial or eye-opening statement, even though it’s very obviously an unimportant and insignificant topic.
Unfortunately he has no idea what he's talking about. You don't add or remove electrons in this manner, instead, the electrons in him interacted with the electrons in the object, and exchanged a CHARGE, aka, voltage. You don't gain voltage by adding or removing electrons, you CHARGE them positively which creates a drain on a negatively charged particle.
When I was in electronics school, one of my instructors spent a little time on this to demonstrate how static electricity works. He also mentioned that photons can act as waves or particles. He used a word to describe photons; I don't know if he coined the word or if it has been around a while. He called them "wavicles."
Always a good experiment to show in high schools. I remember seeing this for the first time, it was such a clear experiment to demonstrate the photoelectric effect
I don't think it would have any effect on most people's lives lol. Not even on the lives of electrical engineers (unless they're working on things on smaller levels like in micro semiconductors circuits. Well then they have to understand the real way energy is transfered in electrical circuits.
Electricians & physicists are ppl & already hav a pretty good idea of how electricity works. I actually wish I fully understood how Electricity basically turns into magic when you introduce magnets (Electro-Magnetic Energy).
@@reallue the basics is that you can generate a magnetic field with moving charges, but an electric field can exist regardless. By making a current (usually through wire) you make charges move, so you then make a magnetic field. There's specifically a component called an inductor that uses that property, and it's a coil of wire. One way it's used is in transformers, where putting two together close by allows their magnetic fields to interact and make a current without physically connecting two circuits together. It does this by having a current go in one inductor, which then generates a magnetic field that passes through the other inductor which would induce a voltage and current into the inductor. By doing this, the transformer can step up or step down the voltage from one circuit to another and helps to bring the voltage down to safe levels for home usage among other things.
We're talking about electrons. What do you think electricity is? How do you think solar panels work? That is material that use the photoelectric effect to convert light energy into electrical charges by freeing electrons within the material. This has everything to do with electricity. @@DARTH-QUIETUS
This was absolutely great. Not just showing the Phenomena very well, also showing the "false " case for the positive charge. This was directly answering my question, if maybe you have leaking current to or from the fluorescent lamp. Perfect execution and explanation. Love it.
I wish I knew how to make applications with stuff like this. Waves and particles trip me out immensely and there are some massive untapped potentials and translations of different types of waves to each other.
Ok let me explain. The top of the electroscope was at first neutral. Later, he added some electrons it by putting some negative charge on it. Now, it has electrons and hence, it indicated some charge(the slant in it shows that). Then he exposed that surface to a light that has enough frequency to knock off electrons, resulting in photo-electric effect. So the electrons are knocked off, and hence, no charge is present. The electroscope goes back to neutral position. Very well shown in the video.
This is great, but how exactly does it prove that light is a particle? If you place a speaker next to it and play a tone through it do the electrons also come off? Electrons are particles too right?
@@YantisOm electron is a particle, and it was displaced by light. And only a particle can displace another particle. Hence, light has both wave and particle nature. But I do have doubt with the speaker one. It *might* displace electrons if the frequency of the sound waves are high enough. I am not sure about that
@@ak_the_gr8 but how it can be that light is both wave and particle ,either it can be a wave or a particle , and can you explain what does light being a wave really mean please
@@relaxingshortsx01 well, there is a proof that light is a wave which carries energy. It is kinda complex but in short, the energy carried by a photon of light is given by E = hv, h = Planck's constant v = frequency The frequency v is the frequency of the wave form of light. It's just true that light does have wave nature. And for the particle nature, I have proved that light has particle nature as well because it was able to knock electrons off the surface.
I know that it is so hard to read all of these comments but I hope this message finds you. You are such a brilliant teacher. Thank you for your efforts my friend.
I learned this today earlier and it still hurts my brain the photon electron thingy is also the reason we know what elements are on planets light-years away because electrons basically move and help control light and colors
At the end if we use smaller wavelenght electromagnetic wave or higher frequency wave (its the same meaning) we can open the arms because fotons ripe electrons from the metal (im turkish my english is bit harsh)
Pretending to understand his videos makes me feel smarter 😅
😂😂😂 I feel you my brother
Lol me everytime he does something that requires more than 3 braincells
I don't really listen and act like it makes sense
Just Wow Cool
Thank you.👍🏿
I'm not alone 🤗😂
😂same here...
This video makes me realize how severely important it is to just *show* students how something works through practical explanation, and not just theoretical
@Sarcastic_Math yes.
now try to show practical
schools lack practical examples. we should better pay this channel than the schools then.
@@prajjwalmalviya Most public schools are seriously under funded. This channel probably already get better pay than them lfmao.
I've Learnt That photoelectric effect is the phenomenon when photons with sufficient frequency hits certain metals electrons get ejected, never really visualized it :sob:
The extra bit with the positively charged plate is a really good addition to this video!! This polarity-dependent aspect of the photoelectric effect is not normally mentioned in physics books.
It’s because he only removed electrons and the positive charge is a hole. He said you couldn’t knock it off because it’s too big but in reality there is nothing there. There is a hole there look for an electron is all.
@@christopherlocke9616- Of course there is a low probability of moving the actual positive particles. Not only are they massive, but they tend to be bound to many other atoms in the solid material. BUT, that still leaves the positive pseudo-particle "holes" as you say, and they CAN migrate to some extent, plus there are the surface charges in adsorbed molecules, particularly water molecules, which tend to coat most things in layers up to hundreds of molecules thick. So indeed, _some_ positive charges can be scraped off and moved around. But the main thing moved around is the negative charges, which predominate the action and the _net effects._
@@christopherlocke9616he said protons cannot be knocked off. Not the holes you mentioned🤷♂️
🧐 Hmm, yes, truly polarity-dependent
which is stupid because people need to realize that light can behave like a physical object, it's an easy concept to demonstrate multiple different particles and their physics effectively
That Einstein dude really knew what he was doing.
And he never got a Nobel prize for Relativity because it was too controversial.
he didnt, tesla came up with the idea and edison stole it and capitalized on it. he is a thief among many other things
@@UteChewbwhen time travel is invented we needa bring him to yhe present cause that mf really gon be amazed by science progression
@@UteChewb Neither for Brownian, motion, EPR, etc,
@@wellesmorgado4797 so true. You'd think he would get an award of some kind for finally proving that atoms exist (Brownian motion).
Bro I went from “ohh thats pretty cool” to “huh?”
Same!
Basically light acts like partials and waves at the same time. Light isn't actually partials or waves, just acts like it in certain places. We call these "partials" photons
If the light has enough energy, it can actually knock partials off of objects. Think of it as a bowl of ping pong balls. If you blow hard enough they'll reach the top of the bowl and be able to escape. The more you blow, the balls will fly out at higher speeds. However if you don't blow enough they won't escape.
Now think of electrons as the ping pong balls. Add tennis balls as protons. Now you can see you'll have to blow much harder to knock the tennis balls out of the bowl compared to the ping pong balls. This is because protons are much bigger than electrons and require more energy to fling out.
At least that's what I remember from highschool physics class
@@moothu So light is a shooty shooty bullet that, if it’s a high enough caliber, will deal damage to the target, but it’s also the song Big Iron (metaphorically, since the sound is in waves)
🤣🤣💯💯
He's missing a huge chunk of prior knowledge about light theory in basic science.
This stuff is so cool! We often hear about particles and how they behave, but not often do we get to see physical demonstrations of this.
If you find it cool, read a real textbook, and write where he made mistakes.
@@ltpetrenko when did he make a mistake?
@@iakinose when he talks about protons.
@@iakinose You either add or remove electrons to induce negative or positive charge, in no instance do you add or remove protons. It's only about electrons.
@@tohaason He said you couldn’t remove protons? So where else was the mistake, I understand it’s worded in a way to sound more possible than it is?
I’m not an expert, but I have read a few textbooks in my time. However, I’m not sure of any specific mistakes he made. If he did I’d like to hear them.
Physics at school❌️
PHYSICS AT UA-cam✅️
well, tbh i learned about this effect first in high school
the flash light was unable to remove electrons because kinetic energy is independent of the intensity of light , it only depends on frequency of light i.e einsteins photoelectric equations :
KE = hf - hf0
however the UV light have enough frequency (f >threshold frequency) thus it knock off the electrons.
**ncert class 12 wave optics** :)
but more importantly it's showing that the sum of many low energy photons can't knock electrons off, while single high energy photons can
Thank you, your the reason I came to the comments because the explanation as to white the flashlight 🔦 did not knock off electrons was due to low frequency (higher wavelength, less energy)
It’s actually dual nature of matter not wave optics
Ncert class 11 photoelectric effect
this makes way more sense.
actually understanding these videos gives you a confidence boost for 15 seconds
The comments do it for me! I didn't realize so many people son't understand what's happening. I think his last sentence could've been more precise, actually. It's more of "light has particle-like properties." Love this guy's demonstrations, but I get nitpicky about his explanations. Science communication is hard.
he's dumbing it down most of the time
@@maddog2314 I thought bosons were particles?
Then imagine for a moment how those of us who don't understand feel.
You get a confidence boost from that? Good for you. All my friends would understand this, so it is not making me feel any special.
the fact that he fit all of this into a short is insane work
Agree
He is Smart .
Agreed 👍
I understand PEE but couldn't understand his explanation bcz of his accent.... I can only understand INDIAN accent.
But it feels great for me to explain such things through practical visuals.
❤😮Not Insane... Respectable! 😅😊
Yes because that’s an actual 100000 lumen flashlight. Or so Amazon claims 😂
Clarification: You're not CHARGING it with positive charges. You're scraping away ELECTRONS from the scope, thus making it positively charged. And because there are less electrons on the scope than it was normally, photons can't knock electrons off the scope, because there isn't any or enough!
In solid state physics, free charge carriers like electrons in the conduction band or holes in the valence band are considered considered particles, so a "hole where an electron should be" is considered a positive charge. You might think it's semantics, but holes are "quasi-particles" that represent positive divergences in the electric field, which is the definition of positive charge (Gauss's law), so it's not just silly word games.
@@zachgoldwater957it is literally just word games
@@tingtang9302 Word games can't explain why boron-doped silicon conducts electricity but pure silicon doesn't, despite the fact that neither have free electrons that could be knocked off using photons.
@@zachgoldwater957 word games do precisely that. 1st year EE?
@@tingtang9302 if youre not actually going to make a falsifiable claim then i dont know what you want me to say to you.
If you didn’t get it: basically what he’s saying is, if light only acted as a wave then a light source of any wavelength should have enough strength to remove the charge from the plate, providing the light has a high enough intensity (enough lumens). This is because the energy of waves can be additive, meaning all the photons would add their energy together to provide the amount of energy needed to remove the charge. Because light also acts like a particle, the ability for light to remove the charge is actually dependent on the wavelength of the light (which is the same thing as saying that it is dependent on the energy of the light particle). In this sense, the energy of the photons is not additive, so each photon needs to have enough energy individually to remove the charge. This is why the visible light at a high intensity couldn’t remove the charge but the UVC light (which has a shorter wavelength) could, even at a lower intensity. Hopefully someone sorts by new and sees this lol
My brain and I think most people intuit waves, vibration and friction far easier than high energy or particle physics so this was really helpful
@@Gin-kz5ss appreciate that, lol I forgot that I had even left this comment. It’s honestly still difficult to understand even in simple terms but I am glad that helped!
_"This is because the energy of waves is additive so all photons"_
If it's a wave there'd be no photons
Lol yeah, you're right. @@GertAllen
Just a detail: if light was a wave only, even
for the right frequencies, it would take a couple of minutes for an electron to
gather enough energy, from the wave, and jump out. But, as we see in the video,
the effect is instantaneous.
"I expect you to remember all of this, it's on the test tomorrow"
test is 4 questions.
Can you just go ahead and fail me now? No need to waste both our time....
The test:
I'll see you at summer school 😭
@@svnhddbst8968 The Test:
1. What won Einstein the Nobel Prize? (1 pt)
…
4. Solve the general case of the Schrödinger equation. (97 pts)
“But if I hit it with a nuclear warhead…”
Then it go boom 💥
Then the electrons would…
bim bam blalalalam
then the apparatus would be in dust 😅
why don't you try it😂
I read this as "photogenic effect" at first, and thought there was some secret trick I could do to not look ugly when I have my pictures taken.
Have you tried rubbing your face with a balloon?
THIS. This is what got Einstein his Nobel prize
Really?
@@14xx07 Yeah!
@@14xx07yes.
his general theory of relativity wasn't very well accepted cuz it was hard to prove. We proved time dilation after his death. Black holes and gravity waves were discovered fairly recently. And his theory still has a lot of elements to prove, like presence of white holes and some stuff with charged particles
@@Dr.Kraig_Renwait white holes?
Is he like Jimi Hendrix, releasing bangers endlessly, posthumously? 😮
Why didn't I have a science teacher like this at school. Very very well presented and simple to follow.
damn i must be dumb as hell then
@@Person-lk1vs Us bro Us
@@Person-lk1vs nah he just didn't make it super clear that the dimmer light had a higher frequency. So higher energy per photon, even though there are way fewer protons. But the number of photons doesn't matter, cuz only an individual photon can knock off an electron
My guess is that usually they are slowly broken down by the administration of the school alongside the parents, throw in bad pay in most districts and you have a perfect storm for disaffected teachers.
I was lucky enough to have a handful of good teachers but unfortunately I was dumb about my priorities when I was that age
I'd suggest that it's probably not that big of a factor. What really matters is is how previous generations had very little awareness that raising kids is a whole other science(not literally), so it's common for many to not have that studying attitude, a crave for knowledge. However, it is changeable if you understand your past better, what made you the way you are in terms of studying and then come up with a strategy on how you can change it.
*works with other things as well
Im just imagining millions of little electrons running around like school kids when the lunch bell goes
Then the UV light turns on and they get punched into outer space.
Yeeted
But then the protons show up and kick the uv light's butt
Thank you, these videos relating to my school syllabus will help me clear JEE
Whoever sold you that "100,000 lumen" flashlight was lying to you.
For real...had a 10k one that was way brighter than that.
The camera auto-adjusts exposure.
He can explain more in one minute than my science teacher can in an hour
But your science teacher gets paid by the hour eh. (and not nearly enough!)
Hope you explain this to us! I'm waiting 😐
@@kanagarajponnappan9595 Pretend I pay you for your time like a job but only when you are actually working. Just for this example since you asked me to explain.
If you take 1 minute to do something I'm only paying you for that one minute. If you take an hour to do the same thing then you are now getting paid for that entire hour. Clear enough? Sorry if that is more of an english language colloquialism.
Good day.
@@Rebar77_real did I ask you anything? Lol i asked Ochxchii
@@kanagarajponnappan9595 Oh, you needed _that_ explained? Good luck then.
Imagine being an middle/high school kid having access to educational video like this, I wish this was possible when I was in middle school, I would have definitely had better score.
I am in this exact situation and i am making the most of it, currently studying math way above my level and understanding it thanks to incredible videos and sites
Currently sophomore year of highschool and love watching vids from this guy, kursgesagt, and others like it, and I can always wrap my head around the vids, but this one just made me audibly say wtf and I'm about to rewatxh it for a 6th time to try to understand
Agreed. And think about kids who still don't have good internet access.
I’m currently living in that right now! I’ll need these videos for tests and stuff later on!
No way dude you’d be a tick tock zombie be honest 😢
Straight up Disney princess moment !! The bird singing with you nd your voice it's just soo magical wow
My brain doesn't allow me understand this much science
I can't believe I've never seen that demonstration before, that's amazing
Me either. These should have been in every high school.
Fun fact: when the plate is charged positive, the light actually kicks electrons out, but they're getting back into it because of the electric force (the plate already has less electrons and "pulls" the kicked out ones back)
What?
Hmm so basically, its like on ionizing radiation where it kicks out electrons on an atom?
Err maybe. How do you know that the top of the conduction band of the metal is still within range of hv of the UV light?
@@dllahr note that he had already removed the electrons from the surface by the principle of electrostatic induction. Hence no electrons.
@@aathi2255 That's what it would mean if the top of the conduction band of the metal is not within range of hv (energy) of the UV light to cause ionization. The top of the conduction band are the electrons that require the least amount of energy to be removed from the metal by the light. If the plate is charged positively enough - if enough electrons have been removed - then the gap between the top of the conduction band and the vacuum level will be larger than the energy of the UV light, and no electrons will be removed. This is a different mechanism than saying the electrons are ejected and then return due to positive charge on the plate. To be clear I don't know which one is happening! Just asking do we have evidence for one mechanism over the other.
I have been studying photonics as part of my work as a manufacturing technician in a fiber optic company. Your videos are a great way of showing these effects in an understandable way.
Explained photoelectric effect in 1 minute 🎉🎉
Giving an object a positive charge isn't from moving around protons, it's removing electrons
No kidding, 50% of what this guy says in his videos is incorrect. I swear he spends 5 minutes browsing a wiki page and then buys some cheap thing on Amazon and makes a video without double-checking anything he's researched or even bothering to understand how the physics of this actually works
Yeah he said that he removed electrons?
Yeah that sounded off when he said that
He said he was removing elections when giving the plate a positive charge.
@@chrisray1567 he said the light wouldn't remove the lidocaine charge because it couldn't blow protons away
For anyone having trouble understanding:
Photons interact with electrons, and even though photons have zero mass (which is why they can travel the speed of light). They can still knock the electrons off the plate with enough ENERGY since electrons have such little mass to begin with (10^-28 grams).
How do we know the photon’s energy? The bigger the wave, the less the energy. Radio waves are as tall as buildings but have very little energy, UV rays are smaller than the pin of a needle but they have way more energy because the wave is more sporadic, like molecules in boiling water.
That’s why the regular light couldn’t knock over the electrons but the UVC light could.
Protons are much heavier than electrons though (10^-24 grams) which is why the UVC light couldn’t knock them over.
Only the positive charge is lack of electrons not presence of surplus protons. Cant knock of something that is not there...
@@imrostoffa9077exactly
@@imrostoffa9077Yeah that part lost me
@@cam5816 As was stated though, you can view electron-holes as quasi particle and be fine, just i dont think it rings the right bell.
I'm still having trouble understanding. 😵💫😅
One of the most entertaining channels on UA-cam. Still can't forget at one point this guy had a spider strength training.
I think the problem with a positive charge is not that it can't knock the protons off since they're too big, but that when the plate is charged positively all electrons go away and the the UVC light cannot put back electrons in
The "all" isn't likely. I expect the positive charge of the plate pulls back any electrons the UV light has knocked out of place. There's nothing else around to attract them, such as a plastic rod with a big positive charge, like was used to induce the positive charge on the device.
@@blairhoughton7918 I see where my words got wrong, I didn't mean to say 'all' electrons are gone. Whenever an object is charged positively, the free electrons are removed, this causes a positive charge, thus, the UVC radiation couldn't bring back the missing electrons, thus it couldn't restore a neutral charge.
@@vihangdalal Some of the free electrons in the metal electroscope are removed, but looking at the indicator it's not close to as charged as it can indicate, which, trust me, isn't nearly as charged as it can get. Even then the UV photons may be acting on bound electrons in the metal atoms not free ones in the conduction band. So the only thing keeping the electroscope from being charged more is the electrons being pulled back because it's the only sink in town.
I wish my school would teach me photoelectric effect like this, i spent 1 week straight just solving questions and numericals on it and i just now got the concept because of your video.
Public schooling is designed to discourage, even ridiculule learning on your own, in about half of nations. This allows for easier insertion of indoctrination and imperialistic propaganda. In is unfortunate, but I believe you may reside in one of those nations. The nations that are not part of the 10 most free nations on the planet are infamous for this. About 65% are guilty of this.
Except, he was wrong. Protons do NOT accumulate like indicated ... that was instead a depletion of electrons, a deficit if you will of electrons, making the charge appear positive.
@@uploadJ He didn't say protons were accumulating. He said that electrons were being removed. He implied that protons would have to be knocked off to discharge it since the photons can't add electrons.
@@facemash re: "He implied that protons would have to be knocked off to discharge"
Hence, an implication they were accumulating. You don't see that? If you don't you don't, but some of us do see that.
@@uploadJ "Hence, an implication they were accumulating"
No. That is not an implication of what he said. That is something you incorrectly assumed based on what he said.
No one else seems to have misunderstood him. Only you.
I love that good old light wave-particle duality!
He says he gives it a positive charge by adding protons😅
@@remcovanhartevelt588no dude, he said “so now im removing electrons” eight after he said he was making it positively charged
@@remcovanhartevelt588 youre too slow to even understand a simple youtube shorts video
I wish we'd stop teaching it that way. It just puts people into a mental hole that proper particle models have to work doubly hard to get them out of. All the wave theory does is show how even complicated explanations that fit some of the data are sometimes simply wrong.
That is a very well-done demo and video on the photoelectric effect. Thank you!
Woah i just completed my modern physics chapter and realized that this is the best experiment for demonstration of photoelectric effect in real life.
This is the best, most understandable explanation of this that I've ever seen. Wow.
Well yes but no. You can't take electrons from your hair and deposit them elsewhere....
Apart from this detail (no need to enter in deeper on orbitals and valence) yeah!
Beautiful demonstration. I have finally understood how photoelectric effect works. The reason no deflection occurs in the first case is that the brightness of light depends on the number of photons whereas the ability to knock off the electrons depends on the frequency of the photon which determines the energy of a single photon. So even though the light is bright but is emitted at a lower frequency it cannot affect the metal plate however a dimmer light emitted at a higher frequency exceeds the threshold frequency and helps knock off the electrons.
Understanding this makes me feel good 😁
in india,
photoelectric effect is taught us in 11th standard in chapter atomic structure
and actually one of the easiest chapter
i follow you because i get the practical approach of my concept thus enhancing my concept
thank you!
Wonderful.
The way you demonstrate the Laws of Photo Electric Effect is simply amazing. I've studied (memorized) for getting marks but this is the first time I see it demonstrated.
Can you explain it to me if you don't mind I didn't get it but , since I'm a curious idiot
I asked you
Please help 😅
Wtf did I just listen to? My professor played this in class...
WHO, in the UNIVERSE, has a 100,000 lumen flashlight?
Happy New Year, Action Lab, the videos are great! 👍
I’m not gonna pretend I understood this at all
Atleast you’re being honest 😀👍
Glad I’m not the only one I thought he was speaking in tounges or something
same. i understood probably 1/3 of that but i just watch to sound smart.
You’re not too smart then are you
Photons carry energy that can be absorbed to eject electrons from metals creating "photoelectrons". Different materials have a different work function. The work function is the minimum energy needed to eject electrons, so if the work function energy is met, an electron is ejected, as simple as that.
In modern times we've come to utilize this effect into more practical things. The photovoltaic effect is the same effect but the electrons aren't ejected, allowing for a much wider spectrum of applications.
Slight correction, the light doesn't need enough energy to knock off protons in the case of the positively charged plate. It just needs enough energy to take away electrons from the plate that already "needs" more electrons. In short the energy should be enough to overcome the binding energy of an electron on a positively charged plate which is higher in magnitude than that on a negatively charged plate.
thats even more BS than he already said. i am astonished by this acchievement.
Came here to say this. If he used an ionizing "light" it would be again slightly different. X-rays, in sufficient quantity should be able to positively charge this.
@@eyeofthasky pls explain to me how this should properly be said because imma need this stuff for school this year and I want to know the right way
@@coinmandylphoton no need to knock knock, just unbind electron.
Hope you get A+.
@@akwa2273 cheers mate
The fact that a man was riding on a train looking out the window and figured out a secret to the universe is one of the biggest W’s this worlds ever seen
"Hello Vsauce here"
Why doesn’t the UV make it more charged by continuing to knock off electrons
Metaphorically: the low hanging fruit is gone.
More scientifically: it is only certain electrons that are easily knocked loose by photons, in the outermost layers of atoms. The remaining electrons require significantly more energy per photon to knock them loose. You'd need gamma rays instead of UV rays to eject those electrons.
frequency is directly prpotional to Kinetic energy of photoelectrons
This was one of the experiments we studied in A level physics, it’s really interesting stuff!
High five, A levels gang
As someone with a degree in physics and EECS, these are good ideas for desktop gadgets and toys that entertain me more than TikTok videos
I can’t even get the grasp off it and someone invented it. It just mind blowing.
I see you’ve met my “UA-cam science teacher as well”. Hats off to this channel 🫴🎩
Had to watch like 5 times, this is so fascinating to see with actual materials and not just pictures. Thank you!
That being said if we could see an artists rendition of the charges moving around that be cool too XD
We had this in grade 12!
I misread this as photorealistic. I though I was going to learn a photoshop trick.
But I’m happier with this.
This is actually the best explanation I've ever seen, and I have BS. in Physics.
What jobs can you get with that qualification? Asking purely out of curiosity
With only Bachelor's degree, I can choose laser enginner, PCB/semiconductor/automobile manufacturing process enginner. But being a middle school physics teacher is much more common.
@@jm2340
This needed a longer video.
There's almost always a full-length video for every short that he posts. There's a full video for this one.
Just check the description of the short.
@@_FrankMatthews_ THANK YOU! lol
(I rewatched this shirt half a dozen times trying to tease out the little details I was missing).
I can return to being productive again!
Whoa some crazy science being understood so easily
Literally only understood this cause we covered this in today's physics class
more lazer an light lesson's, please. can't get enough
Well bigger truth. Actions lab guy has no clue what he is speaking.
Want to learn more?
@@Raytracer111 what is fundamentaly wrong in this video then ?
@@Raytracer111 this comment feels like it has the character of some sort of conspiratorial or eye-opening statement, even though it’s very obviously an unimportant and insignificant topic.
This man will never run out of content and I'm happy
I still felt like I was listening to a foreign language
Its crazy how we just have to sit here and believe it’s true
There's so much information with its physical significance in this video. It just amazes me how this channel manages to provide us with so much info.
Unfortunately he has no idea what he's talking about. You don't add or remove electrons in this manner, instead, the electrons in him interacted with the electrons in the object, and exchanged a CHARGE, aka, voltage. You don't gain voltage by adding or removing electrons, you CHARGE them positively which creates a drain on a negatively charged particle.
This is the coolest shit I've seen in a long while
Light is like your wife, when you say particle she is wave when yoi say wave she is particle😂
Fascinating, I've wanted to see this for a loooooong time, thanks for the upload 😅
The way I half understand this because we’ve talked a bit about this in Chem 1, but my understanding is still so rough 😭🤚🏻
I think it's more part of modern physics topic
Dw this stuff is mainly covered in electricity and magnetism in physics
very nice, just learnt about that in physics a month or two ago. A demonstration from someone like you is always nice to have
I love these videos ,keep uploading
Did not get a word of that thanks 👍✅
Yeah I barely understood what was happening lol.
I reckon your name tells you where your priorities really are.
@@NixonAxi I don't like Miley tbh. This is just a hacked UA-cam account so I don't have to watch ads so I gave it a stupid name in case it got banned
This is an amazing short to end an amazing year. Happy New year
This is absolutely stunning.
When I was in electronics school, one of my instructors spent a little time on this to demonstrate how static electricity works. He also mentioned that photons can act as waves or particles. He used a word to describe photons; I don't know if he coined the word or if it has been around a while. He called them "wavicles."
My guy explained all of the star wars universe in 49 seconds
wtf was i on 7 months ago
hello me from 10 months ago and hello me from 2 months ago
hello me from 1 year ago and hello me from 5 months ago and hello me from 3 months ago
Gandalf, GANDALF! He's being a Wizard again!
Always a good experiment to show in high schools. I remember seeing this for the first time, it was such a clear experiment to demonstrate the photoelectric effect
me sending a trillion protons into the eyes of my enemies
Wow this is really interesting! I know nothing about it, how fun!
if only people knew how electricity really works
I don't think it would have any effect on most people's lives lol. Not even on the lives of electrical engineers (unless they're working on things on smaller levels like in micro semiconductors circuits. Well then they have to understand the real way energy is transfered in electrical circuits.
Electricity has nothing to do with this
Electricians & physicists are ppl & already hav a pretty good idea of how electricity works. I actually wish I fully understood how Electricity basically turns into magic when you introduce magnets (Electro-Magnetic Energy).
@@reallue the basics is that you can generate a magnetic field with moving charges, but an electric field can exist regardless. By making a current (usually through wire) you make charges move, so you then make a magnetic field.
There's specifically a component called an inductor that uses that property, and it's a coil of wire. One way it's used is in transformers, where putting two together close by allows their magnetic fields to interact and make a current without physically connecting two circuits together. It does this by having a current go in one inductor, which then generates a magnetic field that passes through the other inductor which would induce a voltage and current into the inductor. By doing this, the transformer can step up or step down the voltage from one circuit to another and helps to bring the voltage down to safe levels for home usage among other things.
We're talking about electrons. What do you think electricity is? How do you think solar panels work? That is material that use the photoelectric effect to convert light energy into electrical charges by freeing electrons within the material. This has everything to do with electricity. @@DARTH-QUIETUS
Nice recommendation. Much better than physics classes in college
This did feel kind of hard to grasp concept of until the end but it is really fascinating to understand light a bit better now!
"you can't knock out protons, those are too big". Nuclear force wants a word.
Yeah… this guy is bugging. Idk what he’s saying
This was absolutely great. Not just showing the Phenomena very well, also showing the "false " case for the positive charge. This was directly answering my question, if maybe you have leaking current to or from the fluorescent lamp. Perfect execution and explanation. Love it.
Bro taught me what I learnt in a year in a single video
I wish I knew how to make applications with stuff like this. Waves and particles trip me out immensely and there are some massive untapped potentials and translations of different types of waves to each other.
Ok let me explain.
The top of the electroscope was at first neutral. Later, he added some electrons it by putting some negative charge on it. Now, it has electrons and hence, it indicated some charge(the slant in it shows that). Then he exposed that surface to a light that has enough frequency to knock off electrons, resulting in photo-electric effect. So the electrons are knocked off, and hence, no charge is present. The electroscope goes back to neutral position. Very well shown in the video.
This is great, but how exactly does it prove that light is a particle? If you place a speaker next to it and play a tone through it do the electrons also come off? Electrons are particles too right?
@@YantisOm electron is a particle, and it was displaced by light. And only a particle can displace another particle. Hence, light has both wave and particle nature. But I do have doubt with the speaker one. It *might* displace electrons if the frequency of the sound waves are high enough. I am not sure about that
@@ak_the_gr8 but how it can be that light is both wave and particle ,either it can be a wave or a particle , and can you explain what does light being a wave really mean please
@@relaxingshortsx01 well, there is a proof that light is a wave which carries energy. It is kinda complex but in short, the energy carried by a photon of light is given by
E = hv, h = Planck's constant
v = frequency
The frequency v is the frequency of the wave form of light. It's just true that light does have wave nature.
And for the particle nature, I have proved that light has particle nature as well because it was able to knock electrons off the surface.
@@ak_the_gr8 thanks a lot
I know that it is so hard to read all of these comments but I hope this message finds you. You are such a brilliant teacher. Thank you for your efforts my friend.
Bro this is so cool cus im learning this in school rn in ias physics U2, cool to see it physically
You're something else!
There is great things ahead of you, ser! Every video something very interesting!!
✨ *Nice words magic man* ✨
I hope you all had a good year and that the next one will (hopefully) be better than the last✌🏾🕊
I learned this today earlier and it still hurts my brain the photon electron thingy is also the reason we know what elements are on planets light-years away because electrons basically move and help control light and colors
Me staring at the screen thinking I’m understanding something
I like how everyone is struggling to understand this concept, meanwhile in India the photoelectric effect is one of the fundamentals 😭. You guys lucky
At the end if we use smaller wavelenght electromagnetic wave or higher frequency wave (its the same meaning) we can open the arms because fotons ripe electrons from the metal (im turkish my english is bit harsh)
Just learnt this at school
Einstein is an absolute genius to come up with this idea
This feels like a “Eureka!” moment
Now I just knocked myself back in the past about 16-17 years
Excellent work making this video!