discovery of electron well in the discovery of electron we will use five Tools in this experiment the first one is glass tube and we will take some sort of guess in this glass tube for example we will take hydrogen gas in this glass tube the second one is vacuum pump we use this vacuum pump in order to decrease the gas pressure for example we decrease the pressure of the gas to 10 to the power negative 3 mm of HG the third is two metallic stripes one metallic plate is cathode which is negatively charged plate the second plate is inert which is positively charged plate the fourth is high voltage source like battery we need high voltage like 10 000 volt in order to ionize The Gaze the last and the fifth tool is emitter emitter is used to detect the flow of current and the circuit thus we learned that we take hydrogen gas in this glass tube secondly we decrease the pressure of the gas to 10 to the power negative 3 mm-hg using the vacuum pump thirdly we use these two metallic plates having negative charge and positive charge fourthly we use the battery to provide high voltage like 10 000 volts finally this emitter will detect the flow of current now we will learn the experiment part consider this discharge tube which has hydrogen gas at low pressure when we provide high voltage to it we will see the continuous deflection of the emitter now here you have to think like a scientist cathode and inode are not connected I mean there is case between inode and cathode we know that gas is an insulator and current doesn't pass through the insulator but we observe the continuous deflection of emitter which reveals that current is continuously flowing in the circuit my question is how current is passing through the glass tube will we assume two possible solutions of this mystery firstly we assume that something unknown is moving from the inner towards the cathode secondly we assume that something unknown is Flowing from the cathode towards the inord so there is 50 50 probability is about this unknown flow now here we face big problem I mean we are not sure that in which direction this unknown thing is Flowing I mean can we detect the flow of unknown thing or current well we will solve this problem in two parts in the first part we take the discharge tube we create a small hole in the cathode secondly we code the big side of the ketode by fluorescent or zinc sulphide now what is the purpose of this hole at fluorescent screen well its purpose is simple I mean if something is Flowing from inner towards the kid or it may pass through this hole and may hit the fluorescent screen as a result we will see a glow on the fluorescent screen now we will provide the high voltage the emitter shows continuous deflection it means that current is passing through the circuit but the result is nothing I mean we do not detect anything or any glow on the fluorescent screen hence we said that the unknown thing is not flowing from a node towards cathode this assumption our part 1 is badly failed we discovered nothing now in the second part we do the opposite experiment we take this discharge tube we create a small hole in the inner secondly we coat the big side of the inert by fluorescent or zinc sulphide it purpose is simple if something is Flowing from the cathode towards the inode it may pass through this hole and may hit the fluorescent screen as a result we will see a glow on the fluorescent screen now we will provide high voltage the emitter shows continuous deflection it means that current is passing through the circuit but the result is stunning I mean we see glow on the fluorescent screen congratulation everyone we have solved the problem this glow on the fluorescent screen means that something unknown is moving in straight line from the cathode towards the inert let me repeat it this glow on the fluorescent screen means that something is moving in straight line from the cathode towards the inord we call this something unknown as remember that we call this kitodre because this Rays originate are produced from the kittort thus we learned that keto rays are produced in this discharge tube which causes the emitter to deflect and current is continuously flowing in the circle thus we successfully solve this problem now we will further study the behavior of ketotras consider this electric field I am interested to pass kitu dress through this electric field after passing kitu dress through the electric field we observe that cathode rays Bend towards positive plate we know that opposite charge attracts bends towards positive plate and electric field because they are negatively charged let me repeat it the cathode rays bent towards positive plate and electric field because they are negatively charged so we learned that keto dress are negatively charged also remember that keto Rays deflect an electric field and a magnetic field an absence of electric and magnetic field they will move in a straight line hence noted down these important points now we will further study the behavior of Keto dress in the second study in this study we change the material of both the cathode and inert when we provide high voltage we observe that the same cathode rays are produced in this class tube secondly we again change the material of the board cathode and inert again we observe that the same cathode rays are produced so we said that cathode rays do not depend on the type of material they are same for all materials hence we conclude that ketores are nothing but a stream of electron or C of electrons secondly we conclude that ketores are the basic constituent particles of all materials because all the different materials produce cathode rays just remember that we discover cathode rays which is made up of electrons now in the third study of Milliken oil drop experiment we can easily calculate the charge of electron which is equal to 1.6 into 10 to the power negative 19 coulomb also we calculate the mass of electron which is equal to 9.1 into 10 to the power negative 31 kg remember that the discovery of electron is along crosses and many scientists contributed in this discovery but the whole credit goes to JJ Thompson that's why we say that JJ Thomson discovered electron this from all these studies we conclude that the cathode ray starts from ketode and move towards the inward secondly these Rays themselves are not visible but their behavior can be observed with the help of certain kind of materials like fluorescent screen thirdly in the absence of electric are magnetic field these Rays travel in straight line fourthly and the presence of electric are magnetic field the behavior of cathode ray is similar to that expected from negatively charged particles fifthly the characteristic of cathode rays do not depend upon the material of electrodes and the nature of the Gaze present in the cathode ray this week include that electrons are basic constituents of all the materials hence noted down all these important points I hope that you have learned all about the discovery of electron