Chemistry GIFT (GOSALITES INTERMEDIATE FOUNDATION TUNING PROGRAMME) | SAURAV SINGH SIR - DAY - 3

Added: 2026-05-05

[00:00:05]Good evening. Good evening. Am I audible?

[00:00:11]Once just clarify.

[00:00:13]Okay, very good.

[00:00:15]Now, how are you everyone? I hope everyone fine, nice, good.

[00:00:23]Enjoying also?

[00:00:25]Just enjoy. This is your last, I think summer.

[00:00:32]After that 2 year you have to do so much hard work.

[00:00:36]I'm fine. I'm fine.

[00:00:38]So, just little bit enjoy also. Do study also.

[00:00:42]And think about your what can I say?

[00:00:47]Whatever you have selected. You have selected to become a doctor.

[00:00:51]And this journey is like little tough. Tough in the sense it has required it demands so much sacrifices.

[00:01:03]So, I know you are ready to pay this sacrifice because of that you have selected to become a doctor. So, very nice. Very good. And I hope you have revised whatever we have discussed yesterday.

[00:01:16]And now I think I was given one question, a simple question.

[00:01:25]In college is there any entertainment?

[00:01:28]Classes are like that key you will enjoy and we will try to entertain you also and teach you also. So, both will be there. Don't worry.

[00:01:38]So, relax.

[00:01:40]Okay. Now, now come.

[00:01:44]Now come to the point. Point is what?

[00:01:47]Yesterday there was a question I was given.

[00:01:50]What? One calculation. I hope you have done it. Simple calculation was there.

[00:01:55]And we was now in the situation What was the situation?

[00:02:02]To discover proton. Well, discovery of proton I think we are going to start. So, now what happened? When inside the atom, just if I'm saying this is one atom and atom is a neutral structure, neutral particle structure, whatever you want to say.

[00:02:20]This is a neutral body.

[00:02:23]And if it has discovered key inside that electrons are present.

[00:02:29]So, it is a common sense, basic common sense key one neutral structure, one neutral structure and inside the neutral structure if negatively charged particle is available, it means positive charged particle also present.

[00:02:44]And now once electron was discovered, then everyone start to find what? That positive particle which is going to neutralize the structure.

[00:02:57]And that positive particle when they started to discover, everyone is doing what?

[00:03:04]Cathode ray experiment. Different different scientists are using different different method how to find it. And they was trying their best one by one.

[00:03:13]And now after that one scientist was there that has identified that. The name of that scientist was what? Goldstein.

[00:03:24]So, now we are going to start anode ray experiment.

[00:03:35]Anode ray experiment.

[00:03:38]If you will observe anode ray experiment, its setup is also simple, not tough.

[00:03:44]Little changes are there.

[00:03:47]So, first you have that tube.

[00:03:54]In that tube one side anode and one side cathode as usual. So, if I'm assuming it this is the anode plate and this is the cathode plate. So, I have to attach positive part of the battery with this.

[00:04:17]And negative plate will be attached with the cathode part or with cathode.

[00:04:27]After that whatever cathode they have taken here, it was not solid. It was porous or you can say perforated.

[00:04:37]Porous or perforated. So, porous I cannot make here. So, I'm drawing like this. This representation is telling only key it is perforated. Small small pores are there by which anything can move from this side and come this side.

[00:04:54]And now it is attached with the negative plate of the battery.

[00:05:02]Okay.

[00:05:03]After that what?

[00:05:06]After that zinc sulfide screen. So, that screen I'm trying to draw here. This is the zinc sulfide coating. This coating or this paint, whatever you can say, will help us to identify any charged particle hit that or not. So, this is zinc sulfide coating. Very good. ZnS.

[00:05:33]And one more important thing Goldstein has done, that was what? He has not keep the glass tube totally what? Vacant. No.

[00:05:45]He has not taken it vacant.

[00:05:47]He has filled inside that gas. And not only one, different different gas he has tried. So, once we are doing the experiment, same experiment by taking H2 gas and next time we will take helium gas. With two gases I'm going to explain it. And other you can change other gas also you can take. No issue will come.

[00:06:07]Always anode ray will uh generate. But in which manner it has generated, that is very important. So, now here some molecules of H2 gas I am writing.

[00:06:23]So, this time not it is totally vacant.

[00:06:29]Voltage as usual more than 10,000 V or above than that. Well, near to 10,000 V.

[00:06:36]High voltage. This time pressure is not low as much as it was low in cathode ray experiment.

[00:06:45]Here little bit pressure is there because a small amount of gas already we have filled. Now, after that once switch when going to on.

[00:06:57]Switch on.

[00:06:59]What will happen? Now, tell me in the comment box. What will happen? In this high high voltage condition, first which ray will generate? As usual, cathode ray will form first. Which ray will form? Cathode ray. And we all know right now cathode ray actually originated from cathode.

[00:07:22]So, can I draw cathode ray like that?

[00:07:26]This is the cathode ray.

[00:07:31]And these cathode rays will go and hit to those gaseous molecules, what gases atom or gases molecule whatever filled here.

[00:07:43]As well as which one will not hit these gases particles, they will go direct. And um now it here no space is there. Little I'm going to change the diagram. Just think one H2 molecule is here.

[00:08:02]Just one second. One H2 molecule I have taken this side. One H2 molecule take here.

[00:08:11]And randomly from here these cathode rays are formed.

[00:08:18]And think this one is not going to hit anyone. So, it will go hit to the back side of the anode. Means here we will get what? Shining. So, here shining will come.

[00:08:36]Here shining will come. So, first sign, brightness came behind the anode because cathode ray went and hit it.

[00:08:46]But now very important thing.

[00:08:51]After whatever sign came this side, after generation of shining this side behind the cathode also brightness or shining came.

[00:09:09]This side also.

[00:09:12]And obviously this side whatever came, that came after behind the anode.

[00:09:20]So, Goldstein was has idea key when this much con that type of setup and condition he will arranged if he is going to arrange, then obviously cathode ray will generate. So, behind the anode whatever sign came, that is okay.

[00:09:38]Due to strike of cathode ray.

[00:09:45]Here no issue.

[00:09:47]Then issue is where?

[00:09:49]Where is the issue?

[00:09:50]Where is the problem?

[00:09:52]Behind the cathode whatever brightness shining came, that was the question mark.

[00:09:59]And he has initially no idea.

[00:10:04]That so much idea was not there. So, he has just used the common sense. As we and if I am there, you are there, you are doing the same experiment, you will also say "Okay, like behind the anode, whatever rays hits, whatever particles charged particle hits, we said them cathode ray.

[00:10:22]Similarly, if behind the cathode, whatever