discovery of sub atomic particle

• Thomson said that the electron in atom are like seed in watermelon

  rutherford atomic model is currents 3d model

  bohr atomic model is currents 2 d model

  quantum mechanical model is that pqrs model

  
• daltons atomic told that atom cant be divided into piece but can be divied into electron nuetron proton

  
• michal faraday laws of electrolysis all are thinking whether gas liquid solid conduct electrcity or not but later julius plucker his junior prove that gas can conduct electricity(cathode ray experiment) with a conduction THE VOLTAGE SHOULD SHOULD BE BERY HIGH AND PRESSURE OF WATER SHOULD BE LOW

  
• cathode ray experiment by plucker


  Pluckers experiment for proving gas is conductor he in a vaccum cylinder (vaccum is to possible so it means pressure is vert low) at high volt electron passes from cathode to anode by witnessing the glass wall become coloured

  
• properties 1 of cathode ray

  • the mass from the cathode moves towards to anode in linear momentum but through the way the paddel wheel(mica) got moved which means there is some particle like electron moves from cathode to anode

  
• introduction

  
• PROPERTIES 2 of cathode ray tube (have doubt)

  When electric field is applied to a stream of cathode rays, they get deflected towards positive plate. It showed that cathode rays themselves are negatively charged.

  
  

  2) which means in electric field the catode rays it move unproperly towards the positive centre of the middle

  
• property of cathod rays 3

  • When magnetic field is applied, perpendicular to the path of cathode rays, they get deflected in the direction expected for negative particles. This further confirmed that cathode rays are negatively charged
  • this mean in the beam whem we show a external magnet the beam follows the direction of magnet.

  
• properties of cathod ray 4

  • Cathode rays produce X-rays when they are made to fall on metals such as tungsten, copper, etc.
  • cathod rays are produced due to the collision of high energy cathode ray particle with meetal surface

  
• properties of cathod rays 5,6,7,

  • 5. Cathode rays travel in straight lines. An object placed in the path of cathode rays casts a sharp shadow. It shows that cathode rays travel in straight lines.(like light travels in a straight line and if distrub it cause shadow
  • 6. When cathode rays are focused on a thin metal foil, it gets heated up. (because electron is a mass it strike and produce heat according to the law of conservation)

  
• properties of cathod rays continous of previous image

  7.On striking against walls of the discharge tube cathode rays produce faint greenish fluorescence. (due to the walls of the paricular firm)
• properties of cathode rays - 08

  • 8.the vaccum tube means low pressure of 10^-4 so there is will some air in it. so the electron collide with gas and ionize
  • O2+ will move towards postive terminal and e- moves towrds negative terminal

  
• j.j thomson found specific charge in cathode ray

  the charged particle is electron

  • if electric field alone produced (orange plate) the cathode ray (-ve) attract to +ve and strike 1
  • if magnetic field alone then it strikes 3
  • if no distraction (no EF,MF) IT STRIKE 2
  • HE GOT SAME ANSWER OF SPECIFIC CHARGE EVEN IN DIFFERENT GAS IN CATHOD.......BUT IN ANODE IF GAS CHANGE THE SPECFIC CHARGE CHANGE

  
• ROBERT ANDREW MILIKAN to find mass of electron

  • if the oil is passed through X-rays it will ionize thto form cation(-ve) which repels to the (-ve) plate

  
• so

  • Charge of the Electron (-)or proton(+): Determined by Millikan to be approximately -+ 1.602×10^−19 coulombs.
  • because they contain equal and opposite charge for making it stable.
  • Mass of the Electron: Derived using Thomson’s charge-to-mass ratio and Millikan’s charge measurement, resulting in approximately 9.109×10^−31 kilograms.
  • (does mass of proton and electron are different)
• properties of anode rays

  • it travels and defelect (EF,MF) same like cathode rays
  • But the specific charge ( charge to mass ration) in anode will result based on nature of gas present not like cathod
  • that is because here why take mass of anode which has Oxygen nitrogen which has different mass but cathode rays mass of electron is same

  
• G.K

  Cathode rays consists of electron

  but aode rays doesnt consists of proton

  Anode rays consists of positively charged ion such as H+, O+
• but the mass of proton 1837 times higher than masss of electron

  so thats why when we taking mass of atom we never take mass of electron because it is neglliagle smaller

  
• • discovery of neutron (james chadwick)

  • mass of H is 1 and mass of HE is 4
  • but we cant take mass of electron to find mass of atom since its 1837 its heavier(negligable)
  • isolated neutron are unstable so its disintegrates into electron,proton,neutrino.
  • and it is the highest particle and least stable
  • ies density 1.5 * 10 ^14 g/cc

  
• • by cathod rays electron was discovered (j j thomson)
  • by anode rays Proton was discovered (ernest rutherford)
  • by concept of atomic mass Neutron was discovered (jaes chadwick)
  • mass of neutron is nearest (not same) to proton

  
• comaprison

  
• • the radius of nuclear is about 1/10,000 of the atomic radius
  • radii of nuclei is experssed in fermi (10^-15m)
• discovery of radio activity (henry bequral)

  • the alpha rays deflected towards the (-ve) electric field. so alpha rays is positive.
  • the beta rays deflected towards the positve (+ve)electric field so the charge of beta rays is negative
  • the gamma rays not deflected so it is neutral charge

  
• comparison


  here we can see in the diagram beta rays is more delfected than alpha rays even though the charge is higher but the mass of alpha is more in alpha rays so thats why it deflected less