Atomic Structure part 4

本站添加: 2026-05-12

[00:00:00]now coming with the properties of the cathegories now calculate race they have already said you the cathode rays when they strike on the the days of mica foil it produces a shadow on the screen what does it prove it shows that cathode rays travels in a straight line path all right what'd I say oh you've seen in the last class that we have taken this is the cathode ray tube we have taken it all right this is a cathode ray tube we have taken and this is your the electrodes we have taken it let us say this is connected to the positive and the negative electrode you can see it here this is your vacuum pump already we have seen it so if you place a what you can say a mica foil this is a mica foil you are placing in path of the cathode rays then you will find a shadow is we found here on the screen so what does it prove which shows that cathode rays travels in a straight line path I told you also that if you place a mica file the path of the calculator is you see it rotates the microphone is rotating what does it prove that cathode rays consists of particles which tons which contains energy they are energetic particles and as a result energy is being interconverted it changes from one form to another form which one to each form it changes from electrical energy to mechanical energy that is kinetic energy because it is moving the cathode removes other capital moves in the microf I'll move the movement of this mica foil says that cathode rays consist particles which possess energy and E to inter conversion of energy that is electrical energy into mechanical energy you do which it moves mechanical energy you know is of two types kinetic energy and potential energy size it is moving it possess kinetic energy now nexus with cathode rays is falling on a fluorescent screen this screen you know that it is being coated with the fluorescent material we have seen that it glows so when cathode rays falls on a fluorescent screen that fluorescent screen it glows that means it causes fluoro sense all right when cathode rays also the fluorescent screen that is as a screen coated with zinc sulphide goodness I told you so it causes fluorescence because it glows Nexxus calculate ways ionizes the gases through which they pass yes definitely what I said you have to take gas and a very low pressure 0.001 maybe trough mercury you will be taking it so what do you find assignment that the cathode rays passes through it it ionizes the gases it ionizes means suppose if I take a hydrogen gas in it it will cause ionization of the gases here electrons is losing it loses electrons hide induces electron and these electrons only flows from the Kappa to the anode and due to which we have seen it already that would speak prove that cathode rays consist of negatively charged particles so cathode rays causes ionization of the gases any gases I have taken here Adam any other guesses you can see and even find it out that it causes ionization of the gases but minded the pressure has to be very very low but one more thing I'll add it here suppose is that you is completely evacuated miss no gas is been present in a vacuum so will Catherine trade travel how to turn there's a path because here the gas is there which is ionizing this is the path which provides the part and hence it travels from one end to the other end but if suppose the thing isn't I have made the team completely evacuated try to understand I've made that you've completely evacuated no gas is there in it then what do you see no Catherine trees will be produced you say why Hey what is there in it vacuum no gas so no idea it is ridiculous no annotation means no path will minute if no path will be there in between what is that vacuum then half the race will travel from one end to the other end not it so it is same thing just like for example you are having a tube light in your home suppose you know that the tube in that you blend your filling of the gas and the low pressure and hence what you find is that these gas which is spilled under low pressure when you pass electricity through it it gets ionized and dito ionization what I find is that the Rays travel from one end to the other end and hence that you let use initially you see it sparkles and after that it starts glowing yes but due to the course of time let us say after one year 1/2 1/2 year 2 years what happens the gas slow orion slowly diffuses out from the sides 2x the Mexicans are there are the Mexicans body find it becomes what against it'd be the it expands use of how expands when it begets me to them regularly you are you are blowing the village so the metric and gives it EULA and as a result slowly it expands so when it expands variety the gases which is present in it it comes out rather the air enters into it and you know air is a poor conductor of electricity it is a poor conductor of lit city which enters into the tube leg and do it it does not carry current it is not conduct current simply same thing so here what I said when the gaseous is coming out it's completely evacuated do not happen will they it will flow the current will flow no mind in that particular thing next then the categories are allowed to fall on a photographic film on a photographic plate nobody find it you'll find that that cathode rays causes a glow it effects the photographic film how do we know that it affects our photographic film you take that particular film and you go for developing that film you go for developing that particular film we convert it from negative to positive any paper from negative to positive the photography nowadays you are not being all these things because nowadays you click and you get the photo isn't it clear so hence you do not know what is development of a photograph okay so when you are developing the film all right then you find this some spots will be there in that film flat from you go to the particular spots nothing but a cat head race which has travelled it through it so jacquard race also affects a photographic film alright next counter place if it is allowed to fall on a particular metal it causes x-rays alright suppose this is a particular metal at a connect let us say constant Y I consider the tungsten because has got a very high melting mug is a symbol of tungsten you know there is nothing but w so in this way when cathode rays are allowed to fall upon it it's allowed to follow on it then modify decide if that is reflected rays are coming out from which these reflected rays are otherwise known as what x-rays which is a - yes all right which will be studying in the higher classes more about it in details then when cathode rays for the electorate degrees and allowed to fall on a particular metal which has got a high melting point and low ionization energy then cathode ray sorry x-rays are emitted from it all right so the best example if these are constant the X rays are not from it so capillaries produces x-rays we cancel that now character arrays also causes heating effect how do we come to know here you just just put a thermometer you put a thermometer here your gadget thermometer all right you will find the thermometer shows a constant rise in temperature when can hear a sizzle to follow this particular metal now you just put a thermometer here your attention thermometer here you will find that the thermometer shows a constant rise in temperature quite a surprising by the budget so rising temperature same thing inter conversion of energy there is electrical energy changes to heat energy you have to give energy changes to mechanical energy you have tremendous changes to heat energy so there is a rise in temperature so these are the properties of the cathode rays so to see we came to know about the properties of that cathode rays so these are the properties of the cockatrice okay I hope you understood now apart the cathode rays I have to tell you two more things now see actually the experiment was done by JJ Hamza isn't it it was a message it forms an experiment now thomson only worried is that he found out the charge by mass ratio E by M ratio charge by mass ratio of electron and how much he got is the value one point seven six independently power8 who learns by grom he got the value this is being this you get it experimentally you will be studying an experiment that is in plus eleven you'll be selling this module experiment in this particular segment you will be setting how you can relate the charge by mass ratio the Thomson's experiment doing this way now things are they are not saying about it you just to remain just you remember this particular thing that the charge by mass ratio changes from gases to gases it changes in different gases it has got different values because of that so in case of electrons alright the gases which you have taken here you will find the value to be as 1.76 into separate coulombs per gram the values all right now I am saying this particular thing because after that another experiment Millikan another scientist I am I am what I did he found the charge of an electron how did it in this field the solid mass of an electron Millikan he found the mass of an electron how he did it see it that is he divided he divided by e by M now see mathematically even even if nothing but M yes or no so what is the charge of an electron one point six zero 2 into 10 to the power minus 19 Coulomb and D by M ratio is one point seven six centered to the power 8 coulombs per gram so cool epsilon will cancel and you'll be getting the graph so if you divide it you'll be getting the answer to be as 9 point 1 1 into 10 to the power minus 28 ground 9 point 1 1 into 10 to the power minus 2 interior ground this is the five electron in this way it was founded by Millican the mass of militia and charged by mass that issue was founded by Thomson whose value is 1.76 into the parade who loves bug growl all right thank you very much