Charge of an Electron: Millikan's Oil Drop Experiment
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- Опубліковано 25 вер 2024
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How did scientists discover how much negative charge an electron had? Robert Millikan and Harvey Fletcher used the oil drop experiment. They looked an tiny droplets of oil, and balanced the downward gravitational (gravity) force with an upward electrical force. At this point, they knew the forces had to equal, and they calculate the charge on the oil drops.
this man really dropped all these bangers for chem students then said peace out and never came back
This comment didn’t age well
He uploaded a week ago
He returned when the world needed him the most
@@thesamuraix881 true af
words cannot describe how awesome u r
Words cannot describe why I said your name and my furniture stated floating
Just think how awesome milikan was
Agree
Thanks 😂😂
@Daim Ali maybe the least charge which they got should be 160, thus they might have thought to compare it with the other ones too... just like how they measure the mass of an atom comparing it with hydrogen which was found to be the lightest one.
Hey everyone, I'm here to help. If you have any questions or just want to learn more, click on the link in the description above. It'll take you to a page where you can ask me questions.
Hi what the......
Sir!
you are my favourite teacher
Sir how it comes to know that upper plate is negatively charged and lower plate is positively charged?
How does viscosity come in play here?
@@elianahermoine6398they use different metals that have those charges. also i imagine that to confirm if it is negative or positive they would use a magnet and see which side repels and which side attracts
He's such talented teacher.The best chemistry teacher on youtube so far.If there's anyone who compares to him,let me know.I wished he posted more topics.
ben's chem videos aren't quite as good but they have a similar whiteboard type style to them and are super clear and easy to read/understand. bozeman science is also pretty good for bio and chem and idk why everyone likes khan academy so much, they're the blandest videos on here imo
otamanlvhs So true! Tyler's the best! Btw, I think chemistNATE's videos are also awesome :)
Sterling King Bozeman science is quite confusing 😕😕😕
Professor Dave Explains is overall the best for general chemistry (though I do very much appreciate all the others including this channel, Bozeman, The Organic Chemistry Tutor, AK lectures, Khan Academy, Crash Course)
Damn 7 years ago
Why other chemistry teachers can’t explain like this?!
physics teachers can explain this better
Do u really need a simple experiment to be explained this thoroughly to understand? I mean he explained what the relative strength of the electrostatic force with gravitational would do to the drop for 5 solid minutes
@@subhasreeparameswaran1246 did you think of this experiment on your own if you thought it was too easy..
Milikan got nobel prize for this exp. Dont expect your teacher much
I'm learning it for physics lol
Very good video, shame he got mixed up on the charge of the oil drop. The x-rays that radiate through the walls of the vessel ionise the oil drop, hence giving it a negative charge. This also means that the + and - plates need to be swapped, otherwise the electric force would be in the same direction as the gravitational force (+ plate attracts negatively charges atoms)
Hi, I just saw this, and I guess you aren't here anymore, cause it was 4 years ago, but on the off chance you see this.. I am someone who has never had chemistry or physics in their life :) (apart from 2 years in the elementary school, which was, bullshit to say the least) uuuum, I now I need to learn it, so I'm using textbooks and what not plus these video's are helping me a lot. But, what I don't get from this video is why do the oil drops lose electrons when dispersed. I know it might be a stupid question, but please help if you can :)
@@tatjanakomendic8502 , he chose to skip the x ray part plus the charges of the plates need to be swapped , x ray ionizes the air so electrons get attached to the droplet after the droplet goes through the tiny hole giving them a -ve charge.
@@fatimajuma4920 LOL BUT YOUR ARE RIGHT
@@tatjanakomendic8502 they lost electrons after getting ioninized .....
I guess if you loss an electron would you be positive.
you seem to be one of the finest chemistry teachers.
I'm from india, it's very competitive up here.
people only focus on formulae and derivations.
Still he has some mistakes... Read my one in his comment section
i am from india too "thats true"
True sir. Its almost impossible to quench my curiosity. School? They say we will only tell things related to boards. Coaching? Only JEE and NEET. Where the hell do i go?
@@suhani8797 books are a heaven for us and the more you read the better
@Kraptonite yeah that's right.
Best explanation of this experiment on youtube. Hands down.
Bill Rabara hu
Time to revisit this video
I found this video on a random youtube search base on a random youtube comment to maybe see something cool, and this is genuinely one of the most fantastic scientific demonstrations i have ever seen. Your ability to pace the explanations step by step is something i strive to do myself, and your kinesthetic sense to work with your paper stuff is absolutely phenomenal. I was genuinely in awe at every little diagram and how you were able to fluidly make each dynamic object move in the way that you had. This is one of my favorite videos i have ever seen.
You are the reason I got an A in chemistry! Thank you so much for making these videos. If I'm ever confused about something in chemistry, I Always go straight to your videos. You bring clarity to some really confusing stuff. Thank you thank you thank you!!!!
Are you still alive?
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Thanks to you, chemistry is still is my favourite subject. My teacher's ridiculous explanations had made me almost hate chemistry.
I owe you a lot. Thanks a million times.
I must say you're born to teach chemistry
Best teacher ever
The explanation still holds even after 10years🤯🎉🎉
Please come back dear .
We all have been waiting for you and your simple amazing but perfect explanations .😊
You have an amazing talent to explain the most complicated topics in Physics in an easy and interesting way. I love it
Jeez, when you can simplify such complicated stuff and explain them so well, you know, you're such a good teacher. Thank you so much !
I seriously think you don't understand how much this helps me out. I might just make it through chemistry and algebra because of you. Thank you thank you
Are you still alive?
not what i was looking for, but I was really impressed how well you broke this down! I really like your style of teaching
I love these videos! Keep em coming. I'm a math/cs major in university and have decided to re-learn chemistry for fun and these videos are great at clearing up some of the basics.
I was so confused in my Chem lecture about Milikan's Experiment, but this video cleared it right up! Thanks for this :)
Nicely explained Tyler. Just an addition, they use X rays to knock off electrons on the way from negative to the positive plate that is why the oil drop is positive.
thx i was gonna ask that:)
Bro x rays dont just knock off electrons from the oil drops but instead they get ionized and get neagtively charged. The electrical plates have to be swapped with +ve ly charged above
This was an amazing explanation of this experiment. Just wish you had included the x-rays that were put through it to make the oil droplets change charge.
Wow. With every tutorial I am amazed that I actually understand the things your explaining. Very thorough and brilliantly described.Thank you! I am 39 years old and have discovered a real desire to understand Chemistry. I feel that a whole new world is being opened up to me and explained in delightful and clear way.
Your way of explanation is magical!!
You really simplify hard things and make it a piece of cake!
My textbook said that the falling oil drops are given a neg charge by x rays
mine too. I am confused.
Lily Jones yeah, my teacher taught me that it was negative
It works in the same way. The reason they become negative is because the X-rays ionise the air molecules and the delocalised electrons then attach onto the oil droplets causing a negative charge. In this case, the electrodes would just be reversed and the oil suspended again.
Your book is right!!
The reason of aquiring negative charge is that the x rays here is used as a kicking tool, these rays kick out the electrons from the gases present inside and gases get ionized and after that the free electrons ionize the coming oil droplets with negative charge since in this case the oil droplets get electrons and thus it becomes negatively charged and at last Milliakan and fetcher was able to calculate the exact value of that negative charge.
Just discovered this video of yours, first one I have ever seen. You are amazing. So descriptive and easy to understand. Hopefully I can pass my chemistry test tomorrow!
UR EXPLANATION JUST WORKED LIKE MAGIC FOR A 14 Y/O ME TO UNDERSTAND SUCH A DIFFICULT EXPERIMENT AND THE CONCEPT BEHIND IT 🤘🤘🔥🔥🤩🤩🤯
By far the best explanation of how the oil experiment worked. You're the best! Keep doing what you're doing.
idk y i saw this video after 9 freaking years...like an idiot...this video is soo darn awesome....he just teaches this with so much passion that its almost impossible not to understand the subject
Wow great videos ! Besides your explanations, I appreciate the modular-drawing format !
when you have a chemistry test tomorrow and missed this part of the lecture...
this is still relevant seven years later, bless this channel, my ap chem summer assignment is easier now, thank you so much!!!!!!!!
Its quite mixed up .
The exact thing should be that the upper plate is to be + and the bottom plate is the - more over, the oil droplets doesn't contain the positive charge but a negative charge . The oil droplet got this charge from the beam passed through by the x rays
emelith cerbito what x rays
emelith cerbito exactly, beam of xray was passed in second chamber which ionises the the air , expelling electrons from them.
Thus those electrons were capture by oil droplet to from "negatively charged oil drops" and they were attracted by upper tube ( which was positively charged)
I was wondering the same thing! My textbook says the upper plate is +ve and the lower one is -ve. Which one is correct? By the way, his videos are great!!!!
Both ways are right
First case when the x rays provide the oil drops with enough energy so they lose electrons and get a positive charge (in that case el3ctrode is up)
Second case is when the x rays provide other molecules with enough energy so they lose electrons which the oil drops gonna take and get a negative charge (in such case the cathode is down)..^^
How you explain it so confidently and perfectly is beyond me. Perfect explanation thank you so much
I’m writing my physics exam tomorrow and you literally explained it SO GOOD! thank you very much
You forgot the X-ray to ionize the droplets.
mayb he didn't explain it coz it's a very different concept altogether requiring thorough explanation...☺
@@sigmabond1289 maybe...
Right, I was here wondering why did the oil drops get positively charged all of a sudden
yes i saw it
I wish all teachers had the will the patience and skill to teach like you sir
How do the oil drops lose their electrons on their way down?
The air inside fist chamber was ionized by passing X-rays through it.
2:40
for anyone wondering how the oil drops got charged, it was such that x rays were passed through the system, which ionised the gas particles inside it. Due to collison with the gaseous ions, the oil drops gained a charge.
Hope it helps
I like the video! One question: Why do the oil drops loose electrons on their way downwards?
Great effort put into making this video and nice explanation of the experiment..........Love your video
Nobody can explain like this, thank you so much 😇
the quality of a teacher is measured by his capacity to make people learn easy.congratulations
We all can’t thank you enough! U r extremely amazing
You are one of the finest teachers I have come across....the way you explained is outstanding !
This dude is a legend! I was about to bang my head against the wall reading my text book but you made it so simple! YOU'RE AMAZING THANK YOU
Tyler, thank you so muchhhhhh I love you, you helped me pass my chemistry class with an easy A. My teacher was good but in a class of 100+ students its hard to get a one on one attention from professor. Again tank you for what you do.
Great video ..it was very helpful!
But I have a question : Why the used oil ???
Its molecules are larger.They calculated the mass by calculating the density by Terminal velocity formula Assuming the droplet to be a SPHERE
As oil droplets are bigger they helped to calculate.
Water evaporates very easily, oil does not evaporates easily and takes the charge easily since oil is a lipid and does not have a charge
I’m so astonish about the accurate, clear, and easy explanation. He’s a very good professor, congratulations.
Great work .. May God bless u Tyler
Tyler, I'm impressed! I am a 17 year old physics student in Scotland, I also suffer from ADHD/ADD thus making lectures/lessons hard to follow, but you make it easy, so I must thank you. I also wonder, why are your views so low? You have a great channel with awesome content. Keep up the excellent and very helpful work ;)
u r the only reason im not failing chemistry lol :)
I used to think your hand gestures were absurd and annoying but now I really appreciate them
Sir, how and why does the oil drop lose its electron while passing through the metal plates??
That's a point I wanted to comment. They don't lose electrons, the air is irradiated with x-ray and this irradiation rips off electrons from the molecules of air. The oil drops, as they come down through the plate, they "grab" those electrons that were taken off the atoms of the air molecules and this is when the oil drops become negative. And in this case, the plates have to be the opposite to the ones in the video, because then the one with positive charge will be above so it can atract the negative drops of oil.
That was the best explanation I could find for this topic on yt!!
I think you have made a mistake. There are x rays in the real experiment. X rays hit the electrons in the air and electrons split from their nucleus. Oil drops that are sprayed on the air takes the electrons and become negatively charged. The top plate is positively charged so it pulls the oil drops. Other than that your explanation is perfect.
When you think about it you can realize that there is no effect on the oil drops to make them positively charged so there is a mistake. If it is complicated for you, this link explains better than me:
global.britannica.com/science/Millikan-oil-drop-experiment
English is not my first language sorry for any fault.
The Selcouth Girl that's what I was thinking...
You are right, that's true
If the bottom plate was positively charged, wouldn't it repel or push the atom up...the same thing really?
One thing which you can't tell in this lecture
Will you tell the reason why some oil drop looses electron
There is also a radiation producing instrument joint between plates
And the way you teach is excellent
Thanks for such a great job
why do some of the droplets lose electrons on their way down?
maverick7376 ... aahh I see ... thank you!
maverick7376 Why do electrons lose charge using X-rays?
Provide enough energy to an oil drop and you will ionise the drop. You will provide enough energy that an electron leaves the oil drop behind. In this case, this energy is being provided by x-rays.
This guy is awesome. I love how he has the work already written out. I hate waiting for the teachers to write it on the paper because it is so time consuming like Khan academy. Great video. Very easy to understand
can you come in my school and teach? you're amazing!!!! thanks a ton
Crystal clear explanation... Loved it.
It's just outstanding !!!!!!!!!!!!!
This cleared up the confusion in my head. Thank you so much, your videos help me a lot. I wish there were more teachers like you. Love from India!
why do the oil lose their electrons when they drop down????
+Ethan585790 Every other model on the planet that i found shows the opposite.
+Jingwen Li same asking why???
+Ethan D. is CORRECT !!!!
Jingwen Li some oil droplets losses their electron because when they falls from up to down then they collide with each other and due to friction they losses their electrons
good question
I normally think of this experiment as imparting a negative charge to the oil drops. and the charged plates being reversed from how they are represented here. Can you discuss this please.
Jeah problem is that they don't know the mass of the drop right...
Sir, I'd just like to say that your way of explaining is perfect. Thank you very much for this
how they measure the droplets mass?
Before turning on the electric field, the droplet is allowed to fall and reach terminal velocity. At this point, the force from gravity is balanced by the force from air resistance (the drag force). The terminal velocity allows one to determine the radius of the oil drop, (both the force from gravity and the drag force are dependent on the radius). With that obtained, the drop can be (hopefully) assumed spherical and the density of the oil is known and voila, one can calculate the mass.
@@lordchipmonk1 But how they measured charge of electrons in Coulombs when you need a charge of electron to measure Coulomb in the first place 🤯🤯🤯
Your videos are so great! They are really helpful! Thanks and keep making awesome videos.
I noticed a minor error in the video. You have written Coloumbs instead of Coulombs. I was very surprised when nobody mentioned this in the comments.
but when the forces balances, shouldn't the oil drop keep its current motion(in this case, a constant velocity)?
You are right, the velocity will not be zero unless it is pulling by another force greater than the force of gravity.I am confused too.I think they should measure the velocity of the oil drop in order to know when it is constant.
But here xternal forces are acting on it right? Gravity & electric force
@@abibliophileananya OMG can't believe this was a comment i made 7 years ago. So much has happened. I graduated college and went through law school and now I'm a lawyer.
@@davidwu3417 woaah that's just so amazing!!😭never realised so much could happen in 7 years...what an epiphany it might be to see your younger self in an old study video related to science and now you're in such a great position as a lawyer!! Makes me wonder what life will unfold for me in the next 7 years...
Veryyy happpyy for youu though! Seriously it's a big achievement and I Hope you achieve greater feat in future!!
@@abibliophileananya Thank you my friend for the kind words! I wish you all the best as well!
Congratulations sir👏👏.
Even digital animations can't explain chemistry the way you do.
Better than best!
You have to use the formula Fg = Fe !
Fg = Force of gravity.... equal to m * g
Fe = Force of the electrical field.... equal to E * q. where E is the electric field intensity and q is the charge of the oil drop.
I think you got the charges of the plates reversed. Also, you didnt say anything about the xray that he used to add charge to the oil droplets. Research again please. And redo this video.
Also he omited details for a better understanding of the general idea dont be so arrogant.
mkkim18 I was responding to the other guy
I love how people have the balls to correct someone without knowing that they're 100% right lol
I have watched several videos on this experiment. This one is the best so far.
The amount of paper this guy uses... xD
This is like the best video on the oil drop experiment. I tried reading 3 books about this but couldn't understand this. This guy just made it so easy!
You always explain things so clearly, thanks!!
excellent teaching by mr.tayler dewitt.he explains each and everything cleary in an easy language so that everybody could understand. wish he was a teacher in our school!!
Fact I support about u(not only that, I admire them)
1.ur IQ
2.ur teaching technic
3.ur use of words...wait I just can't list all of them it's just "u r the best"👌💯💯💯
Your teaching methods are out of this world. You put great effort into your preparation and you are simply a great teacher. Thanks for being a teacher.
I have to agree with previous commentary, this is a top-rate explanation and I truly appreciate the thought and design you put into it. You have lucky students!
Wait,wait,wait... How is it that you read the book a 100 times but do not get a thing and you watch just one video and all the information fixes into your head in a matter of seconds?
I was so stressed about my exam and all went away after watching this video!
Gear explanation👍👍 I hope our teachers adopt this style of teaching, things would be much better and a lot easier to understand!!
Your explanation is cooler than the experiment itself.
I loved this. Like, i got it. I got it before halfway theough the video. But you very thoroughly covered the idea so that literally anyone could understand it without coming across condescending.
Wowow. This helped a lot! I really like the visuals you give!
see the previous comment 1rst... viscosity of the air is known as it stays same at fixed temperature. and v=Terminal velocity. vT is found by measuring the time for the oil drop to fall down through a known distance after the electric field is switched off. vT=distance/time. By using: mg=6*pie*n*r*v. find the radius (r), and substitute it into this equation to find the mass of oil drop: mass= density of oil/[4/3*pie*r^3]. By knowing mass charge can be found by using: mg=Q*V. Find the charge (Q)
Man you got me through college and goddammit you helped me achieve getting all 5 of my uni offers, 3 being Russell Group. I thank you for making everything so understandable to the point yet informative. On to my last physics assignment. Hopefully see ya later and thanks a million times over 🤍🤍!
upload more videos man??!
11 years ago, still the best
5:24 unlike charges attract each other , this means that the base plate would attract the negatively charged oil droplet
Tyler you're like an explanation guru. LOVE. Don't stop making videos...you're saving lives lol! :)
WORLDS BEST EXPLANATION I HAVE EVER SEEN!
Thank u sooo much! I've never seen a teacher explaining this way,u make it so much easier to understand!
god...!!! it's such a relief to get your video for any concept....coz I'm always sure I'll get it here!
you are the most amazing teacher ever you are so passionate and you are happy to teach which makes me wanna learn and listen to you which is hard for me to do because i was abused by many of my teachers. they keep saying i am dumb but now i am trying hard to prove them wrong and you are the main reason for my future success. keep doing what you are doing Mr.Tyler!
I really appreciate you for bringing up such material to the public. I appreciate your efforts and work!!
You are the best chemistry teacher I have ever seen
Best Chemistry Teacher Thus Far
Can you do more videos please🙏🙏🙏🙏
This is what education feels like curosity not pressure and burden