I've struggled to understand this since childhood (I'm 30 now), but this actually went into my brain this time. Thank you so much, Kathy :) Recommending to any other friends who struggle with the, "How does it work though?" question.
Thanks, I only learned this stuff in my 30s and I was shocked at how simple it was. If you haven't seen my videos on Galvani and Volta you might like that too, I always find that the history makes the science much more accessible.
You're overstating the case regarding lying electricians. I was taught about electron flow and conventional current in the 1970s when I was doing engineering science at school. The same happened in my electrical and electronic engineering degree. It's a pity there was this initial confusion, but the equivalence of the two concepts doesn't cause confusion in practice. Take a look at "Basic Electricity" (part 1) by Van Valkenburgh [Technical Press, 1954].
Hi Kathy, Excellent explanation and succinct on how a battery works. Will use this with my daughter, studying year 11 chemistry this year. Greetings from Melbourne, Australia Harry
I got quite a charge from this video. Thanks! In my long career, I have wasted too many hours arguing about current flow direction with fools. For first order circuit analysis, the direction of current flow can be ignored. But, the less education the other person had, the more certain they were that they were right. Youth is an age of information and maturity is the age of wisdom. Conclusion, I am now wise enough to not argue with fools. :) )
5:40 one correction: tho: alkaline is generally basic because it's about the alkali metals within the first column (Na, K, etc) or the alkaline earth metals in the 2nd column (like Mg)... but NOT ALL bases are alkaline. In fact, of the three metals mentioned about that particular battery, only one (Potassium) is an alkaline. :-B
In the day, my teachers explained the reality, then the Franklin flow as a convention. They said we could work the problem either way, without mixing conventions. Brooklyn Tech is a great school.
Teachers and electricians are not lying. Convention vs. "Reality" is by necessity. Too much technology is based on the convention. The math works both ways. And getting something backwards while something else is not can kill you. "Current" flows from positive to negative. Current produced by moving charges flows from negative to positive. And old tube electronics and motors follow convention. Modern electronics follow current flow instead of convention. Stay safe.
Hi A key neglected fact, crucial for operation of batteries and for LIFE (electron transport system in mitochondria) is the fact that pure water is a very poor conductor of free electrons !!!! Electrical current in aqueous solutions is carried by ions (both positive & negative)...
*Funny historical anecdote:* Heisenberg failed to explain how a simple lead battery works during his Phd defence. The examiner of experimental physics, Wilhelm Wien was infuriated.
Hulkster I knew that Heisenberg almost failed his PhD because Wien was disappointed in his experimental knowledge but I didn’t know it was a lack of ability to describe a simple battery. I love details like that. Where did you hear that?
@@Kathy_Loves_Physics Also: "When Sommerfeld came back from Madison in the spring of 1923, Heisenberg returned to Munich from Göttingen to finish his doctorate. To that end he had pursued a project in mathematical fluid dynamics, unrelated to quantum theory but a steady topic. His doctoral examination was nonetheless a struggle. Because he had to show mastery of physics in general, experimental as well as theoretical,Heisenberg had grudgingly enrolled in a laboratory course under the supervision of Wilhelm Wien, professor of experimental physics at Munich. Wien was a distinguished researcher whose careful measurements of the spectrum of electromagnetic radiation had been crucial to Planck’s 1900 introduction of the quantum hypothesis. But the curmudgeonly Wien, conservative in science as well as politics, was skeptical about Planck’s innovation and openly detested the quantum theory of the atom that his colleague Sommerfeld was forging. Wien was thus naturally disposed to show some hostility toward Sommerfeld’s latest wunderkind, and the young man’s ill concealed disdain for experimental matters only made things worse. At Heisenberg’s oral exam in July, Wien pelted the candidate with questions about his laboratory work that he should have been able to answer easily enough but, through his own neglect and indifference, was not. Wien wanted to know the resolving power of a certain optical device. Heisenberg couldn’t recall the textbook formula, tried to work it out on the spot, and got it wrong. Wien was appalled. Only after tense negotiation with Sommerfeld would he reluctantly affirm that Heisenberg had shown an adequate knowledge of the broad range of physics.The brilliant young man got his doctorate, but with a grade barely above a mere pass." *Source:* Uncertainty. Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science - Lindley, pages 105-106.
That is a very good question, and a little complex but I will try to explain it. OK, so I think it works like this, you don't get more chemical reactions due to a temporary dip in the potential (voltage) unless *both* the negative electrode loses electrons and the positive electrode gains electrons. So, imagine you connect the negative of battery A to the positive of battery B. Some of the electrons from A will move to the positive electrode of B, but the voltage across A and B will remain at 1.5 Volts. The voltage across both A & B, however, will be 3 Volts as it is cumulative. Now, if you put these two batteries in series in a circuit, then the electrons in the negative electrode in battery B will push the electrons in the wire to add extra electrons in the positive electrode of battery A. In this case both Battery B and A will have more chemical reaction which will cause more electrons from the negative electrode of battery A to move to battery B. This process will continue until the batteries are dead. Does that make sense or is it too confusing?
Hi Kathy, I realize this video came out years ago (I'm catching up lol.) Just a thought. What if after Ben Franklin's time the definitions of negative electrons and positive protons were reversed? Diodes were marked oppositely (maybe not since they seem backward, or at least the schematic symbol is) as were electrolytic caps and batteries. Then, his assertion that electricity flows from positive to negative would be correct. Perhaps it wasn't he who was wrong, but the definitions afterward. Great videos! I'm loving 'em! Keep up the good work. Happy new year 2020!
Hi Ken, So, Franklin defined positive as the charge that was left on a glass rod if rubbed by silk. Much (much) later it was found that when you rubbed glass with silk the silk gained electrons and the glass lost electrons, so, by Franklin's definitions, the electron had to be negative. [Actually, it was a bit more complicated than that, in 1894 or so it was found that a stream of "cathode rays" where negatively charged (or had the opposite charge of a glass rod rubbed by silk). It was then found that the cathode rays were made of tiny particles that were in everything. Eventually, those cathode rays particles were called electrons and people found that the motion of those particles are what current really is composed of. If you watch my video on JJ Thomson and the discovery of electrons it might help]. Also, xkcd has a cartoon about Franklin and charges because of course he does: www.xkcd.com/567/
I first learned basic electronics in '72/'73 with the Air Force. There I was taught that current flowed from negative to positive. When I got out of the Air Force I attended college for Electrical Engineering. There I was taught that current flowed from positive to negative. It took a little extra effort for me to switch that concept around.
Had a strict teacher in Vo Tech shop that had strict beliefs. Told us there is NO such thing as a AA, AAA, C or D battery but is nine volt batteries. AA, AAA, C & D 's are dry cells ! Also told us only two things can store electricity a leddly jar & a capacitor. Batteries & dry cells store chemical energy that is converted to electrical energy. In my 50 years as an industrial electrician never cared or had to be concerned if in DC circuit direction of electron flow. Worked on hundreds of 2 to 250 HP 480 Volt VFD'S that had but capacitor bank and had AC converted to a 665 volt DC buss to feed IGBT'S but didn't care about electron flow while troubleshooting.
Madam, I have one more query. Why Battery Doesn't get Discharge within itself, Electricity Flowing from electrode to electrode within the electrolyte and become all neutral? I don't know. If possible please make me understand.
I don't know if I missed it but did you show how the electrolyte in the battery acts as a catalyst to force electrons from the positive side to the negative side? That is how batteries placed in series have increased voltage.
Thanks for sharing your knowledge I want to know one thing so please help me in understand it If you connect two cell in series then how the chemical reaction takes place and how voltage will gets added with respect chemical reaction
Yashwanth L in my mind, the best way to think of it is with an analogy: imagine you have two water pumps, if you put them side-by-side you can pump water to the same height but you can pump more water. If you use both of them in series then you can pump water to a higher height.
@@Kathy_Loves_Physics thanks for reply one more question i have in electric vehicles battery are used,cells are connected in series how charging will happens when cells are connected in series
5:45 lol - it drives some chemists nuts too. There are conferences on the standardization of naming conventions. ie. IUPAC.org Unfortunately there doesn't appear to be room for that sort of thing on my bucket list.
I had a Chemist friend who got stuck teaching freshman Physics and he refused to teach that current goes from positive to negative! I kept on telling him that he was going to confuse his students mightily if they took any other physics or engineering class but he was adamant that it was ridiculous.
One thing I've long wondered about is why all dry cell batteries produce 1.5 volts no matter how big they are. You know, AAA, AA, C and D are all 1.5 volts (and I know that the rectangular 9 volt batteries are just a bundle of 6 small -- I believe "F" size -- 1.5 volt batteries in series).
OK, let me try to explain. The different sized batteries all have the same chemical and the same types of metal so they all produce the same voltage. However, the bigger battery has a lot more metal and chemical so it can produce a lot more current for a longer period of time.
I think you got your explanation of the charge flow a little twisted. The Positive terminal is where the electrons physically are, the negative terminal is where the positive ions are; that's the issue with conventional current. So current does flow from positive to negative terminal, but only because they flipped the symbols from the physical reality. The way you explained it gives the impression the electrons are physically at the negative terminal & they're flowing to the positive terminal; which would be the case if the symbols were applied correctly.
Kinda begs the question: Why weren't electrons defined to be positively charged and protons negatively? Seems to me Franklin did get it right and the atomic physics got it wrong. (Considering they came much later in the game and could have used his definition as a basis.)
Every scientist and electrician is lying? Funny, I learned that electricity flows from negative to positive in college back in the early 80's. Yeah, the convention is indeed reversed for the reasons you stated, but both in Electrical Engineering and in Physics, my professors made it clear that it was negative to positive. So, no mind blown here. 🙂 I took a course in Electronic Material (non-EE Engineering course), and bam!, suddenly my earlier courses in chemistry made a ton of sense when it came to conductors and insulators ... crystal lattice structures and so on.
@@Kathy_Loves_Physics Science itself is a cool stuff, but adding a story telling way of narration with some cool history makes its more listenable...Thanks for the nice videos maam.. :)
The attempt to explain batteries in this video is 'Not even wrong' (as Pauli would have said) -- quite unworthy of such an otherwise excellent channel. So, I looked around on youtube to see if someone else might have succeeded in what Kathy attempts here. The path between [a] too much weird chemistry terminology and [b] an approach that is 'friendly' but marred by quasi-nonsense is admittedly a difficult one to find, but my search of a half-dozen videos turned up one at least that succeeds in finding that narrow path. See the 9-minute video linked below. The issue: What makes a battery work lies almost entirely within the electrolyte solution, not in the electrodes, not in the wires attached to the electrodes, not in "different metals.". To focus on "different metals" -- as in Breaking Bad, Season 2, Episode 9, for example, or in minute 6 of Kathy's video here -- results in distractions that lead nowhere. Only if one talks about paired REDUCTION and OXIDATION events (not necessarily using those terms which are admittedly confusing, 'overloaded' and unfriendly) has one explained "how a battery works." And by the way, for one or both electrodes, one may choose metals that are chemically inert. And the talk about 'free electrons' has to do with conduction in wires, not what goes on inside the battery to which those wires are attached. Those are two entirely different subjects that Kathy has conflated all through her presentation. Here is the video I mentioned that succeeds in a presenting a friendly explanation of how a battery works, with minimal jargon: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-6p6UkwbEdtQ.html
That's funny. The books I learned electronics in use the electron-flow method, not the conventional-flow method. I heard the the way egineers learn it.
Shibam Mukhopadhyay you had a good teacher. He or she must have also told you that “conventional current” goes the other way or you would have been helplessly lost in your next physics or engineering class no?
Every Electrician and Scientist is lying? Well Kathy, as an Electrician there are two aspects of electricity 1) electron flow 2) current flow. These go in opposite directions. Electricians are only concerned with current flow, and will install current limiters, current interrupters, current measurement devices and current meters. Not concerned at all about electron flow. As that is our perspective how are we lying?
Yes, most electricians only care about current as defined as the thing that flows between positive and negative terminals. But what is flowing between positive and negative? Nothing. This is even more apparent when you talk about cathodes and anodes. Faraday defined the cathode as the terminal that the electricity flowed from and anode as where the electricity flowed to. As this was done like 60 years before the discovery of the electron, engineers define the positive as the cathode and the negative terminal as the anode (as they still do). However, this gets super confusing when it is obvious where the electricity is coming from in a cathode ray tube. In that case it was apparent from the very first that *something* was emanating from the negative terminal. So they called the negative terminal the cathode. It is fine to use a slightly inconvenient code that is incorrect because it is too difficult to change it after all of this time. But most people incorrectly think that it means that something is flowing from the positive to the negative terminals when, really, electrons are flowing the other way and we just define the current as opposite of the electron flow (unless we don't talk about it like with CRTs). Lying may be too strong, how about misrepresenting what is really going on?
Kathy Loves Physics Kathy, you say ‘nothing flows between positive and negative’. What about current, which is the working component of electricity? This is what we measure and revenue meter and have to install Current Transformers when the current is too high. How would you measure or revenue meter electron flow?
@@peteroconnor5537 You measure electron flow in exactly the same way you measure "conventional current" by deflection of a magnet. It is just that the direction of electron flow is opposite of the direction of current. But we are far too far down the rabbit hole with too many electricity systems setup for "conventional current" that we are stuck with this, even in cases, like cathode ray tubes, where it doesn't make any sense.
Kathy Loves Physics Really Kathy? You know of a way to measure sub-atomic particles? Who makes such a meter if it exists? Surely current does flow, it flows from positive to negative, it can be quantified, measured and metered in both AC and DC and has to be so in order to work in the practical world, which seems to be different to a Physicists theoretical world. BTW, have enjoyed all your vids so far. Just questioned this one. Cheers
Great information but I intensely dislike the soulful “electricity” singing at the beginning and end of these videos. It’s very disjointed from the overall tone and somewhat brash sounding.
A reply! Thank you - I get the atomic-ness of it, but it still seems a kind of mystery - electricity itself seems like a real effect that I can understand, but the effect of charge and magnetism is still a sort of mystery. I don't get the movement of particles and the effects of electricity. @@Kathy_Loves_Physics
James SS it seems like you are feeling more confused about the relationship between electricity and magnetism rather then how the battery works. Have you seen my video about how Oersted discovered how current creates a magnetic field? (I think it is easier to understand physics from its context) Here is a link: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-2yawV5ekyN0.html
Thank you for the message. I appreciate your efforts to reply. My op was a joke to be honest. I am interested in the subject, sometimes I think it's beyond me. I will watch your video. @@Kathy_Loves_Physics
