This eighth-grade science lesson is about electricity. Specifically, it focuses on heat that is generated by conducting electrical current. It is the 19th lesson in a sequence of 24 lessons on electricity and its functions. The lesson is 53 minutes in duration. There are 37 students in the class.

00:00:09Please teach us well.
00:00:13Okay then, please take out your handouts that I handed out yesterday.
00:00:29Okay then first, look at your neighbor's sheet,
00:00:33and see if they have their results written and
00:00:38check to see if the contents are all the same.
00:00:43Check that over a little bit please.
00:00:46Don't worry about the way you express it.
00:00:48Since your expressions will vary
00:00:50from person to person.
00:00:56Okay then someone be the representative and
00:00:59check the contents.
00:01:08B:The positive terminal...
00:01:13B:The negative terminal...
00:01:22Uh, I had you check the kind of gas
00:01:25that was generated by using things like
00:01:28incense and matches.
00:01:31So I'd like to check the results from that,
00:01:34the name.
00:01:37Okay then, the positive terminal,
00:01:39who has the confidence to give me the answer?
00:01:41Yes, Yoji-kun.
00:01:50Okay please go ahead.
00:01:52(Which one was it?)
00:01:53The positive terminal.
00:01:54It burned vigorously.
00:01:56Yes. And? The name of the gas is?
00:02:08Okay then, the negative terminal.
00:02:10Who is confident?
00:02:18You were reviewing over here just a moment ago,
00:02:20right? Okay.
00:02:32Is that okay?
00:02:33Check it over okay?
00:02:35Then the part for examinations and summarizations.
00:02:38Uh, when you exposed water to electricity...
00:02:45Oxygen and hydrogen.
00:02:46Yes, it separates into to
00:02:48two separate substances of oxygen and hydrogen.
00:02:51Okay, that's the conclusion, right?
00:03:21Since you expose it to electricity,
00:03:24you call this type of separation...
00:03:29uh, Chihiro-san.
00:03:30What kind of separation is this called?
00:03:34Yes, electrolysis.
00:03:51Okay, electrolysis.
00:03:53And this is what we did yesterday.
00:03:57So today, what we'll be thinking is water.
00:04:01Being exposed to electricity,
00:04:05it can be separated into hydrogen and oxygen.
00:04:09So what happens in the opposite?
00:04:15What I mean is if we have hydrogen and oxygen,
00:04:18is it possible to make water?
00:04:24If it was this way.
00:04:26How would it be if the arrow was pointing this way?
00:04:29This is what I would like to consider today.
00:04:36Okay then, now discuss with your neighbors
00:04:40to see if you think you can make water
00:04:43from hydrogen and oxygen.
00:04:48If you suppose that you can,
00:04:50then talk about how you could do it.
00:04:52So discuss in depth and think about it please.
00:04:55If you suppose that you can't do it,
00:04:57then talk about why you can't do it.
00:05:00Okay then, go ahead,
00:05:02discuss it with your neighbors.
00:05:04And I'll have you present your answers later,
00:05:06so have it a little summarized.
00:06:23You are always thinking of
00:06:25something so unconventional.
00:06:29Looking at your textbooks may-
00:06:33Think of your own answer.
00:06:35I don't want the textbook's answer.
00:06:39What do we do?
00:06:46But this-
00:06:50But this... what?
00:06:53This is hydrogen //and this is oxygen //so.
00:06:54//Yes... //Yes.
00:06:55This is the resolution that I just talked about right?
00:06:57That's the resolution.
00:06:58You're thinking about the opposite right now, //right?
00:07:00Oh, the opposite, the //opposite.
00:07:01//You've already done this in an
00:07:03experiment so you know you can //do this.
00:07:05//I know I can do this but.
00:07:07This way okay? The arrow.
00:07:08Make that //the other way.
00:07:09//Okay then, all I need to do is do this to this.
00:07:10Yes, so think how you can do that? If it's possible.
00:07:14Teacher forces it together.
00:07:16Am I going to force it together?
00:07:18Okay then, take out your notebooks.
00:07:26Take out your notebooks and first,
00:07:28copy down what I wrote on the blackboard.
00:07:33Okay? Below the yellow box it says:
00:07:34"your thoughts" "everyone's thoughts."
00:07:39So as a continuation of that, uh,
00:07:41summarize what you discussed with your neighbors please.
00:08:25Did you write it?
00:08:29I'm surprised you got this.
00:08:31I just wrote it how I saw fit.
00:08:33However you saw fit?
00:08:47Hurry up and take out your notebooks and write.
00:09:30Teacher. You see the equipment
00:09:32for the experiment in the front?
00:09:34Yes, that?
00:09:35Yes, that, rubber, rubber,
00:09:38what was it that we used?
00:09:39A pin, what was it?
00:09:40The pinchcock?
00:09:41Yes, the connection for the pinchcock.
00:09:43Isn't it possible to take it off once, and
00:09:45then stick a straw in it to connect the rubber part?
00:09:47Oh, like this?
00:09:48Yes. Can't you do that?
00:09:49Well, this side is hydrogen and
00:09:50this side this oxygen.
00:09:51So that means by connecting it
00:09:53you do what to the hydrogen and the oxygen?
00:09:55You have to put them //together.
00:09:56//You put them together.
00:09:57//If you put them together
00:09:58//Mix them, mix them.
00:09:59then you think that you can make water.
00:10:01Okay then, that's one thought. Write that down, okay?
00:10:02Is that okay?
00:10:03That's okay.
00:10:05That's one kind of thought.
00:11:11Okay, even if it's just a little bit,
00:11:13write something down okay?
00:11:15And as that thought as the base,
00:11:17we'll expand on it.
00:11:44Okay, is there anyone who wants more time?
00:11:46Okay then, a little longer, okay?
00:12:09And by the way, since it's rather difficult
00:12:12to just grab oxygen out of the air,
00:12:15we will be using this.
00:12:17Oxygen. It's in here.
00:12:21Give it to me, teacher.
00:12:21Okay? It's in here.
00:12:23Now we have it but what should we do with it.
00:12:26Teacher, give it to me.
00:12:27As for hydrogen,
00:12:28I'm thinking of making it on my own step by step.
00:12:32I'm thinking of making it.
00:12:33So I can prepare the oxygen and the hydrogen.
00:12:36Okay, so how will this connect to water after this?
00:12:41Disintegration in mid-air.
00:12:42Disintegration in mid-air?
00:12:45Teacher, can I have that?
00:12:48There is a limit to our resources.
00:12:51I can't waste anymore.
00:12:57What should I do about oxygen.
00:13:03Okay then, I'll start asking what you think.
00:13:15Huh? Yes.
00:13:17Okay, hydrogen and oxygen...
00:13:19what do you do in order to...
00:13:22make water? But first tell us
00:13:24whether you think water can be made or not.
00:13:27Which one do you think is the case?
00:13:30You can.
00:13:31You can. Okay.
00:13:33What do you think you should do?
00:13:35Uh huh, go ahead.
00:13:41Cool it.
00:13:42Cool it. Ohh, cool it.
00:13:59Cool it. Oh, I see.
00:14:02Okay then,
00:14:08You can or you cannot do.
00:14:10You can.
00:14:11You can. Then the method.
00:14:13Warm it up.
00:14:15Warm it up. Totally contrastive.
00:14:20You can do it.
00:14:29Hmm, Hikaru-san.
00:14:33You can or you cannot.
00:14:34I think you can do it.
00:14:35You can do it. What's the method?
00:14:37Heat it up.
00:14:38Heat it up.
00:14:43Hmm, heat it up.
00:14:53Okay then, I think I'll ask one more person.
00:15:00Lets see... Yumi-san.
00:15:06You can do it. What's the method?
00:15:08Cool it.
00:15:09Cool it. The method is to cool it.
00:15:12Yumi-san, why did you think of cooling it?
00:15:28Oh, cool it. Okay then,
00:15:30I'll ask the whole class.
00:15:31Stop what you're doing please.
00:15:33Uh, I have hydrogen and oxygen prepared.
00:15:38Now all I have is them prepared.
00:15:40So can I or can't I make water
00:15:42from hydrogen and oxygen.
00:15:44Raise your hands.
00:15:46Who thinks it can be made?
00:15:50Okay, thank you.
00:15:52Who thinks that it might not be possible?
00:15:59You think that it can be done.
00:16:01Okay. Actually, there are many ways
00:16:05to make water from hydrogen and oxygen.
00:16:10There are many ways.
00:16:12In other words you can do it.
00:16:15Yes. It's just that when it comes to the method
00:16:18of how it can be done,
00:16:19well I'm sure that some people have
00:16:21thought of other ways than these to do it but-
00:16:23rather than otherwise,
00:16:25this type of answer is the closest.
00:16:32I think so.
00:16:34Okay so now, you won't know unless you see it
00:16:37with your own eyes,
00:16:41so since there's only one piece of equipment,
00:16:43today we will use this area-//
00:16:47//What about over here?
00:16:48I want to make it over there but,
00:16:50for convenience's sake.
00:16:51Teacher what about over here, over here?
00:16:52Okay, then will all of you
00:16:54come gather over here please?
00:16:56And will the people already here
00:16:58put your things away.
00:17:04Yujiro-kun, this, this, here. Okay.
00:17:12Teacher, aren't you going to mix them?
00:17:13Huh? Mix it.
00:17:21Excuse me Yoji-kun,
00:17:23will you make some space for me please.
00:17:25No, it's a little far.
00:17:29A little. A little more, a little more okay.
00:17:32You know, since I'm so thin.
00:17:36Let's see, Kojima-kun
00:17:38sorry, will you turn off the light please.
00:17:47Okay, then first, it says to heat it,
00:17:53but if we just take the
00:17:55heating method straight up,
00:17:57then all kinds of difficulties arise.
00:18:00Why do you think that is the case?
00:18:02Does it break?
00:18:03Hm? Hikaru-san, why?
00:18:08Something about oxygen and hydrogen
00:18:10blowing up or something on that order.
00:18:10Or something that order?
00:18:13I don't know.
00:18:14Well, hydrogen//is actually-
00:18:16//(inaudible) boom!
00:18:18Yes, right. It goes boom, right?
00:18:21Will you stick this between there? There,
00:18:25stop fooling around.
00:18:28Okay, so now
00:18:31//Ouch, ouch, ouch!
00:18:33in order to be safe //about heating it up,
00:18:35we will be using a machine like //this.
00:18:37//Put electricity through it...
00:18:39put electricity through it.
00:18:43Pay attention to this part.
00:18:45Hey, it just snapped or something.
00:18:48What are you going to do?
00:18:49That was scary.
00:18:51What would happen if you put your hand in there?
00:18:54If you put your hand in there.
00:18:55Shh. Can you see?
00:18:57Hiromi-san can you see?
00:19:00I'm going to do it again.
00:19:06So what this means is
00:19:07as a way of lighting it,
00:19:09lighting a match like this is not
00:19:11the only way of doing it, but
00:19:13using electricity like this is one way of doing it.
00:19:16So we'll be using this to do it.
00:19:19So what are we going to use.
00:19:21Something like this,
00:09:22one that's a little bigger than this one.
00:09:26First of all, hydrogen and oxygen must meet
00:09:28inside of here in order to react, right?
00:19:30So we are going to have them meet.
00:19:31Like Shinya-kun said,
00:19:32we are going to have them meet.
00:19:34We're going to mix them?
00:19:35Yes we're going to mix them.
00:19:36And then after that,
00:19:39if you just do this really fast, then
00:19:41the person who lit the match will be in danger,
00:19:44so let's try doing it like this.
00:19:47Like this.
00:19:48Send electricity.
00:19:50Yes it is scary.
00:19:51Look in this area, okay.
00:19:54It's going to snap.
00:19:55It's going to start snapping.
00:19:59Oh, it's not working.
00:20:02Wait a second, okay?
00:20:03I think it's broken, teacher.
00:20:06Hmm. Wait a second okay?
00:20:11It's not doing it, teacher.
00:20:12It's not doing it is it?
00:20:13It might not be working.
00:20:14I think you should give //up.
00:20:16//Teacher the small one//.
00:20:17It's okay, we don't have to give up.
00:20:18This part is scary//. This part is scary.
00:20:19//Teacher the small one (inaudible).
00:20:24Can you tell? Can you tell?
00:20:26Oh, it's doing it a //little, it's doing it a little.
00:20:28//I don't get it because I can't see.
00:20:30You don't get it because you have bad sight?
00:20:32Again. I'm going to do it again okay?
00:20:33Because I can't see.
00:20:36Wait a second okay//?
00:20:37//It's not really doing it right now teacher.
00:20:39Wait a second okay?
00:20:41There's one more, I'll try using this one.
00:20:47Teacher, this one is not working too well.
00:20:49Right? It's not working too well is it?
00:20:53It was working really well.
00:20:55Okay, let's try it with this one. Okay.
00:21:00Teacher, this-
00:21:04But you understand the theory
00:21:06behind how this works right?
00:21:08You send electricity and spread sparks
00:21:10through it and...
00:21:12Can you tell?
00:21:16Can the area near Hiromi-san see as well?
00:21:19So in this way, you don't actually have to
00:21:22directly do this to oxygen in order to ignite it.
00:21:25Okay then I would now like to conduct
00:21:28an actual investigation.
00:21:31Okay then, please get some water.
00:21:37Okay then from there, from there// get the stand, please.
00:21:39//That might hit Aoyama and spill.
00:21:42Okay, sorry. That, that stand.
00:21:48Okay, Naoto-kun, will you please
00:21:51get that test tube that's standing up.
00:21:54What about oxygen, teacher?
00:21:56Okay, please get the oxygen cylinder.
00:22:05Oh, please bring the whole thing.
00:21:10Okay, and then will you get the beaker
00:21:13with the transparent liquid inside of it, please.
00:22:17Okay, then we are now actually
00:22:19going to utilize this and-
00:22:22Try doing it.
00:22:23Yes, let's try doing it.
00:22:27It's not working too well.
00:22:34Please turn off the water.
00:22:36It's cold!
00:22:38Teacher, (where is the) hydrogen?
00:22:42It's kind of scary. It's kind of scary.
00:22:44Okay, thank you.
00:22:45Teacher (inaudible).
00:22:49Hm? Is this putting it too far inside?
00:22:51Wait a second okay?
00:22:52It's long so, one more time,
00:22:55excuse me for a second okay?
00:22:57It's cold!
00:23:08Teacher, you should take your hands off of it
00:23:10after you put it in.
00:23:12Okay, but this one is a little crooked
00:23:15but forgive me okay?
00:23:17Okay, then tighten the screw right there please.
00:23:20A little more, maybe we should raise it a little more.
00:23:22Okay. Something like this.
00:23:23Okay, that's good.
00:23:34Let's do it a little more like this.
00:23:35Okay then, lets first try
00:23:37to generate some hydrogen.
00:23:41How? Put this//, in this.
00:23:45//Don't spill it, okay?
00:23:50And then now this.
00:23:53What is this colorless transparent liquid?
00:24:00Sodium chloride.
00:24:02Hm? Aoki-san, what could it be?
00:24:05Yes, diluted hydrochloric acid.
00:24:08You do this with diluted hydrochloric acid,
00:24:10hydrochloric acid, and then-
00:24:11It's coming out, it's //coming out.
00:24:12//It's coming out isn't it.
00:24:13However, I won't send the bubbles
00:24:16up the tube immediately. Why is this?
00:24:19The air, the air portion.
00:24:22You have to let the air out.
00:24:23That's right.
00:24:24There's some air left over here
00:24:27so in order to make it 100% hydrogen,
00:24:30you must first let the air inside escape.
00:24:35Teacher, it's not going in.
00:24:37Oh, sorry. Like this, "pi, pi, pi."
00:24:42Why are you laughing?
00:24:43Like this, "pi, pi, pi."
00:24:55We're looking so forward to this.
00:24:57Okay, is that good? Okay, that's good. Okay,
00:25:00it's only the first time so this should be fine.
00:25:02And I've already put hydrogen in here.
00:25:05Okay then, the next thing will be oxygen.
00:25:09I would like to take the oxygen from this.
00:25:20Okay, it went in.
00:25:21You only need that little?
00:25:23Okay then, with the method that I used
00:25:25a moment ago, I'll send sparks in here
00:25:28where the hydrogen and oxygen are, and
00:25:33okay, I'm going to start.
00:25:35I'm going to make it react okay?
00:25:41What if it goes baboom!
00:25:46Okay then who should I ask to ignite// it.
00:25:50Someone who's name sounds like ignite.
00:25:52Who's //that going to be?
00:25:55Okay then... Taro-chan?
00:25:57Hm, Taro-chan sounds good but
00:26:00I think I'll ask Kitani-kun.
00:26:02Kota? Which one? Kitani Kota?
00:26:04Okay, pay attention to this area.
00:26:07Okay, pay attention to this area first okay?
00:26:12Okay then Kota-kun,
00:26:13//please put this on the positive side.
00:26:15//You mean Kota-kun right?
00:26:21Oh, water!
00:26:22//Did you see it?
00:26:23//That was too fast man.
00:26:25Water! //Water!
00:26:25//Did you see it?
00:26:26//Say something before you do it!
00:26:29Okay, Kota-kun, this was a huge success!
00:26:34Hm, huh? What did you notice, Shohei-kun?
00:26:39Boom! And then?
00:26:41Oh, it increased!
00:26:42What increased?
00:26:44The water increased.
00:26:46How do you know that it's water?
00:26:48Uh, Yuri-san,
00:26:49see anything kind of flash...
00:26:52did you have the time to spare to see?
00:26:54No way.
00:26:56You didn't.
00:26:57Okay then we'll try it one more time.
00:26:59What? One more time?
00:27:02Well let me tell you, I think you'll be
00:27:05used to it the second time so
00:27:08instead of just going, "Whoa!"
00:27:11watch it okay? Watch it okay?
00:27:13Okay then, I'm going to be on stand-by
00:27:15like before for a little okay?
00:27:19What? Okay then-
00:27:20Let Kota-kun do it this time.
00:27:22This time...
00:27:24I'll have you guys do it
00:27:27from the hydrogen part.
00:27:30Let Kota-kun do it (next).
00:27:33Oh, I got caught.
00:27:36Okay then let's have Yukawa-kun
00:27:38put the hydrogen in.
00:27:42The hydrogen producer.
00:27:49Okay, that's fine, okay, okay.
00:27:51Okay then, Yukawa-kun,
00:27:53put the hydrogen in please.
00:27:56Okay, stand up and do it please. Don't sit down.
00:27:58Do it until about the second hash mark.
00:28:00About here, okay.
00:28:02//This much? This much?
00:28:04//Okay, then Yo-kun, Yoji-kun will you
00:28:07watch this here? About two, okay?
00:28:12Okay, go ahead.
00:28:18Not yet?
00:28:19Not yet.
00:28:28Don't get scared. Watch it.
00:28:32Don't close your eyes.
00:28:35Hey Yukawa, you are off line.
00:28:37It's okay, Yukawa, it's okay b
00:28:38ecause it already went to the second hash mark.
00:28:40You scared me. Three more drops.
00:28:42A little more.
00:28:50Hey, let's not make any ridiculous voices
00:28:53during the experiment, Machida-kun.
00:28:57Let's do this seriously. Do not involve danger.
00:29:03A little more.
00:29:05Let's increase the quantity
00:29:07just a little more than before. Just a little.
00:29:10How much?
00:29:11A little more.
00:29:16Okay, that should be fine.
00:29:19Okay, then put it back on the test tube holder.
00:29:21Okay, then Yoji-kun, do you want to do oxygen?
00:29:24Okay then oxygen.
00:29:26Just add a little, just about one hash mark.
00:29:29Don't put a lot in.
00:29:33Okay, go ahead.
00:29:37I can't seem to muster any strength.
00:29:41Wait a minute.
00:29:43It won't come out.
00:29:45It won't come out.
00:29:46It'll come out.
00:29:47Shall I do it?
00:29:49Try one more time.
00:29:51A little more.
00:29:54Okay, too much got in this time. Okay then.
00:30:00The long awaited.
00:30:03Uh, for the next igniter-
00:30:06I would like one of the girls to do it.
00:30:07Taro, Taro-chan-ko.
00:30:07Why not Taro-chan?
00:30:21Okay, then, the person who could
00:30:27conduct the yesterday's experiment nicely-
00:30:38Let's have you challenge this today as well.
00:30:41Okay then it's ready to go.
00:30:44Wait a minute okay?
00:30:45It looks a little irregular.
00:30:47Kiyomi-san,over here,
00:30:49come around over here please.
00:30:57Okay, it's ready.
00:30:59After you turn it on,
00:31:01all you have to do is turn the lever to plus.
00:31:03Okay then, since I was told last time that
00:31:06you didn't have time to get yourselves ready,
00:31:08please tell us that you're going to turn it
00:31:10before you turn it.
00:31:11Okay, please go ahead.
00:31:12Don't say that you're going to turn it after you turn it.
00:31:13I'm going to turn it.
00:31:16Hey, something flew off!
00:31:17Something flew over here!
00:31:20//Hydrochloric acid, hydrochloric acid.
00:31:21//were you able to notice some kind of
00:31:23change over here this time?
00:31:25What kind of change was it?
00:31:29Boof. Flash.
00:31:30I couldn't see anything.
00:31:31It// looked reddish
00:31:32It //molded it.
00:31:33//It felt like my //heart was going to jump out.
00:31:34//Huh? Huh?
00:31:35It looked reddish.
00:31:36It looked reddish. What about you, Hikaru-san?
00:31:38You closed your eyes?
00:31:41What about you, Yumiko-san?
00:31:43There was a flash.
00:31:44There was a flash.
00:31:45It was distortion.
00:31:46What about you, Kaoru-san?
00:31:47Her hair was //shining.
00:31:48//It looked like it was shining?
00:31:52Okay, then one thing okay?
00:31:55When I had Yukawa-kun and Yoji-kun fill this up a while ago with hydrogen and oxygen, the total amount of gas was just below three hash marks.
00:32:07Right? Just below three hash marks. It was about here okay? However, with the ignition and explosion, the water... has come up to just above one hash mark.
00:32:21So what that means is that due to the ignition, the gas inside this has been-
00:32:22Hm... well before you go straight to it becoming water, what happened is that the gas was definitely used, and gone.
00:32:27Became water.
00:32:37There's nowhere for it to go right? So the gas was definitely used, and then a reaction occurred.
00:32:45Okay then, if water was actually made in here, (and if we were to) investigate. What kind of method would you use to go about investigating that water was actually generated inside of here?
00:32:55Cobalt chloride paper.
00:32:58Yes, if you use the cobalt chloride paper, you can confirm the fact that water was made right?
00:33:03It's just that it's a little difficult in this case. Since it's all being done inside of water.
00:33:10Drink? Hmm.
00:33:15Okay, I see. Okay, then please return to your seats once.
00:33:21Teacher, there's some gas coming out.
00:33:23Hm? There was some gas coming out? Okay then, Yujiro-kun, I'm sorry but can you bring this up front? You can take that off. //Over there too. Will you take that too?
00:33:31//Since I am the assistant.
00:33:34All of this?
00:33:35Yes. Will you bring it over to my desk over there?
00:33:40Okay, Ajima-kun, I have to ask you to do something.
00:33:41Yes, what do I do?
00:33:42The stand and-
00:33:50What do you want me to do?
00:33:54Oh, bring it over here.
00:33:59Oh, just the way it is. Oh, you can take it off if you want. Can you get it off? Do you know how to take it off?
00:34:06Is this okay?
00:34:07Yes that's okay.
00:34:08Okay then I would like everybody to... open their textbooks.
00:34:19Okay, that's all right. Page 81 in your textbooks.
00:34:44Please look at Diagram 7 in your textbook on page 81.
00:34:52The equipment that we just used is drawn here, right? It's drawn right? Okay, there are two things that I would like you to add to that. The first thing is-
00:35:16There rubber stopper is like this, and this part here is put in like this, right?
00:35:29Okay? It's right here. It's emphasized a little here by being drawn large and it's a little separated right? Copper wire.
00:35:37So by the copper wire being separated, what did we want to do here?
00:35:45You just saw it didn't you? [simulating spark noise]
00:35:49Sparks flew.
00:35:58With the energy from the electricity, we cause sparks and we eventually wanted to produce an ignition, right? So this is purposely cut off and is okay.
00:36:10Okay then, please write this down. You may write this in your textbooks.
00:36:37Since danger is accompanied by igniting it directly with a match and it's also difficult, yes. But now you can see it in the picture, right?
00:36:49That this kind of thing occurred inside of our plastic container. Right?
00:36:55So what that means is, okay the second one, is written here, the compound gas of hydrogen and oxygen right? Okay? Will you take your pencil and circle it, please?
00:37:08The compound gas of hydrogen and oxygen. We collected hydrogen and oxygen in order to make water right here.
00:37:17However, actually, when you ignite it like we just did, it causes an explosive reaction.
00:37:23So therefore, this type of gas is called, and with the meaning of it producing a huge reaction in the future in its' name-
00:37:36It is called hydrogen detonating gas at times. Write this in your textbooks please. Detonating gas. Like an explosion. Boom. It's telling you that it will cause an explosive response.
00:37:57So if you look this word up in some small dictionary, and you look under detonating gas, then you'll find that the explanation is the explosive reaction for hydrogen and oxygen.
00:38:10It's written like that so look it up. Yes, detonating gas. It's a word which you are not familiar with, isn't it?
00:38:21Teacher, did you make that yesterday?
00:38:24No, last year.
00:38:28Teacher, have you used that one many times?
00:38:31Because it's about this time of the year.
00:38:36How many times did you use it?
00:38:38How many times, which one?
00:38:44Okay then write what you learned in your notes.
00:38:51What you learned.
00:39:12Write it in your notes.
00:39:19Just make a list, like the first thing was this, the second thing was this. Something like that is fine.
00:39:47Okay then, I think I'll have you come up to the front and write it.
00:39:50What you learned.
00:40:03Okay then the first person.
00:40:09Yujiro-kun. Aoyama Yujiro-kun. Right here... okay.
00:40:20The second person... let's see... Kaneda-san.
00:40:35The third person... Kambe-kun.
00:40:46Okay, when you've summarized it, then come up to the front and write it please.
00:40:50You may write it in your own way.
00:41:41Yes, it's okay.
00:41:55Write down what water is made of.
00:42:12Hm? What is it? You can look. You can look as you write it.
00:43:30Okay then, since we've have a few written up here, write your own ideas in your notebooks please.
00:43:37Okay then, I've had three representatives write what they thought. Kambe-kun thought that water was made from oxygen and hydrogen. Shoichi-kun.
00:43:50Parenthesis two. Uh, Kambe-san right? When you mix hydrogen and oxygen, it explodes. The third one is Yujiro-kun. Water was made from oxygen and hydrogen.
00:44:09So how would you summarize what these three had to say in one sentence.
00:44:17It was this first theme right here, right?
00:44:20Is it possible to make water from hydrogen and oxygen? And since we were able to do that, as a conclusion, we are able to write that type of a breakdown.
00:44:29Okay then, will all of you write your own answers, please. Like that. Using signs, like arrows.
00:44:39For those of you who don't know, I'll write it up here so please copy it down.
00:45:24It got a little crooked. Water is created from hydrogen and oxygen. Parenthesis, since I had you write it down, it is explosive. However, it is an explosive reaction.
00:46:13No, teacher.
00:46:15Not, "No, teacher." Hurry up and write it.
00:46:34Teacher, we have parasitic worms in our body, right? What do you call the thing in your intestine that's really long?
00:46:42A tapeworm?
00:46:44That's it.
00:46:51Don't use an equal sign. Use an arrow. It's a common error but it's not an equal. unlike the mathematical equal, it's not necessarily equal, so yes it's an arrow.
00:47:03That was a good place to make a mistake. It's better to make it now. There's a lot of third years who write equal.
00:47:13Okay, then this is the last thing.
00:47:22Right here, I had you write this last time, but water separates into hydrogen and oxygen. It separates so it is a decomposition.
00:47:30Especially since you're sending electricity so we called it electrolysis.
00:47:33In the case over here, you are making one thing from something and something, so we call this a chemical combination.
00:47:40A chemical combination.
00:47:48A chemical combination.
00:47:50So it means that decomposition and chemical combination is the opposite reaction. So from now on we will continue our discussion with this chemical combination.
00:48:09Okay then, since we took the time to do the chemical combination, we will go right into a chemical combination experiment in our next class meeting.
00:48:17Please look at the same pages 80 and 81 in your textbooks.
00:48:30What are you doing?
00:48:36What are you doing?
00:48:46What we just did was hydrogen and oxygen. It was a gas and a gas to make water, but this time I'd like to try it with a solid matter and a solid matter.
00:48:54And what we're going to use is iron.
00:49:01And sulfur. You read that as sulfur.
00:49:06We are going to mix these two things that, at first glance look nothing alike and... in other words, what I'm saying is let's try a chemical combination of the two.
00:49:20Okay then. I talked a little about expressing substances with symbols at the end of the first quarter, and it has been // one month since then, but do you remember it?
00:49:35[bell ringing]
00:49:44What did, how did we express iron as a symbol?
00:49:48Heat? Heat?
00:49:55Fe. Okay then what about sulfur?
00:49:59S. You seem to have a lot of confidence. S. Okay we'll be using these substances. Okay then, it's this handout right? Will the group leader collect them and bring it up to me please.
00:50:14We will finish.
00:50:16Stand up.
00:50:35Stand up straight.
00:50:38Face the front and stand up straight.
00:50:40Face the front.
00:50:49Thank you very much.
00:51:00Are the names on there?
00:51:11Hey, why... what were you doing that time?