Discovery of proton. I will teach you the super easy method to master discovery of proton. First of all, we will learn about the cathode rate tube. Cathode rate tube contains five parts. The first part of cathode ray tube is a glass tube. We take gas in it like hydrogen gas. Remember that hydrogen gas helps electrons flow smoothly in the tube. The second part of cathode ray tube is vacuum pump. We use vacuum pump to decrease the gas pressure inside the glass tube. For example, we use vacuum pump to decrease the gas pressure to 10 raised to the power minus3 mm of Hg. The third part of kathode ray tube is metallic stripes like cathode which is negatively charged and anode which is positively charged. The fourth part of cathode ray tube is a high voltage source like a battery. We use high voltage to ionize the gas inside the glass tube. For example, we need 10,000 voltage to ionize the hydrogen gas. The fifth and the last part is Mmeter. It is used to detect the flow of current inside the cathode ray tube. Thus we learn that we take hydrogen gas in the glass tube. Secondly, we decrease the pressure of gas to 10 to the power minus 3 mm of Hg using a vacuum pump. Thirdly, we place two metallic strips cathode and anode inside the glass tube. Fourthly, we use high voltage source like a battery to produce 10,000 voltage to ionize the gaze. Finally, we use Mmeter to detect the flow of current inside the cathode ray tube. Now we will quickly revise the concept of electron discovery which will help us to master discovery of proton. We know that JJ Thompson took a cathode ray tube. He made a small hole in the inode. He coated the back side of the inode by zinc sulfide or fluorescent screen. He then provided 10,000 voltage. As a result of this the emitter deflected and cathode rays started flowing from cathode towards inode. These cathode rays passed through the inode and hited the fluorescent screen due to which glow produced on the fluorescent screen. Remember that these rays are called kathode rays because they are generated by the kode. Later different experiment revealed that these cathode rays are negatively charged which we called electrons. Thus Thompson Baba successfully discovered the cathode rays which we called electron. If you want to learn more about cathode rays and discovery of electron watch our video and its link is given in the description. Before discovery of proton first of all we need to learn discovery of kal rays. In 1886 a German physicist goldstein discovered kal rays. He took a cathode ray tube. He performed the opposite experiment. Instead of inode he made a hole in the cathode. He coded the backside of the kathode using fluorescent screen or zinc sulfide. Then he provided high voltage like 10,000 voltage. As a result of this high voltage, he observed that something from the anode is flowing towards the cathode. I mean he observed that some rays travels in the opposite direction to the well-known negatively charged kathode rays due to which glow produced on the screen. He called these rays as inode rays because these rays were produced by the inode. Also remember that these rays were traveling opposite to the cathode rays. Secondly, these inode rays are also known as canal rays because they pass through the canals or holes in the kathode. Secondly, Goldstein Baba performed an experiment to find the nature of canal rays. For example, consider this external electric field. Gulan Baba passed these canal rays through the external electric field. As a result he observed that kal rays bend towards negative plate. It shows that kal rays are positively charged. Similarly these kal rays also deflected in magnetic field and a direction opposite to the cathode rays. Remember that in absence of electric and magnetic field cathode rays move in straight line. So we can say that Goulen Baba was the first person who observed positive particles inside atom. Let me repeat it. Goulen Baba was the first person who observed positive particles inside atom. Also remember this very very important point. He didn't use the word proton. That's why we say that Goulstein Baba didn't discover the proton. He only discovered kinal rays which give the first proof that positive particles exist inside atom. Noted down that this story doesn't end here. Another Baba Rurford Baba took this discovery even further and discovered proton. Now we will learn Rtherford's approach who discovered proton. In 1917, Rtherford Baba took alpha particles and nitrogen atom. We know that alpha particles are like helium nuclei which has two protons and two neutrons. Secondly, the nitrogen atom has seven protons and seven neutrons. He performed a nuclear reaction. I mean he bombarded the nitrogen atom by alpha particles. Ratar for Baba observed that a high-speed particle hated the screen. For example, when alpha particles collided with a nitrogen nucleus, the nitrogen nucleus absorbed the alpha particle for a short period of time and formed an excited florine 18. The florine 18 is highly unstable. It decays into oxygen 17 and hydrogen nucleus. From this experiment, Rather Ford Baba concluded that this high-speed traveling particle which collided with the screen is hydrogen nucleus. And he called this hydrogen nucleus as proton. Remember that this was the first time a nuclear reaction produced proton. It proved that proton is the fundamental particle inside the nucleus. Also remember that this was the first nuclear reaction in which Ratherford Baba artificially converted one atom to another like he converted nitrogen to oxygen 17. This discovery opened doors to modern nuclear physics, radioactivity, fishision and fusion. Finally, let me teach you one of my favorite questions. Who discovered proton and when? Well, the answer is Ratherford Baba. Rutherford Baba discovered proton in 1917. Remember that many students say Goldstein discovered proton. It is totally wrong. He discovered kal rays not the proton. Hence this was all about the discovery of proton.