As Close as You Can Get to Chemistry Magic! | John Thomas | TEDxYouth@ABPatersonCollege

[Music] [Applause] Thank You jasmine for that lovely introduction she has to say nice things because she's in my class and if she didn't you'd be in trouble tomorrow good evening ladies and gentlemen I taught at this school senior chemistry probably for the last 12 years and before that in the UK for many more years I'm passionate about chemistry I've taught it for so many years I'm still enjoying it to this day as I was saying the the thing about chemistry is is obviously the best subject in any school curriculum it is fascinating it's interesting and it's something I believe you need to make them alive because students obviously remember it better and if you cannot a bit of fun while you're teaching something which is potentially quite a challenging subject then it's obviously going to be a good thing so basically what I thought I'd do tonight is just show you feel the little experiments that I do with my students I'll explain what I'm doing and if you have any questions I'm more than happy to answer them in the email that mr. woozi sent it said something like chemistry magic show I believe but at the risk of disappointing you I'm afraid there's no magic here these are just chemical reactions I do accept to a physics teacher they may seem like magic sorry so without further adue pretty like gas in that balloon there anyone know what it is shut out you think helium suggested good suggestion but not correct hydrogen is the only other one it could be there the two like gases I do have some helium in this balloon here but that is full of hydrogen how can you tell them apart because they both are very like they don't kind of look any differently there is a very simple way helium is probably one of the most boring things imaginable it's an element that there's nothing at all it's so unreactive it really is very boring if I was gonna do I'm gonna do that one in a moment a helium you would be very disappointed so there's nothing much I can do with helium except for one thing didn't make my voice goes like that over that thing okay on the other hand this is hydrogen already not used to this so you know doing it by the book here we go no thank you no nice and boom nothing spectacular but obviously a nice little reaction nice playing ice fireball and so on I'm gonna show you some various reactions there's no plan or anything like that but just random experiments and when I said earlier there's no magic in this well actually this next reaction I think perhaps is as close to magic as you could can become but to colorless solutions here what I'm gonna do is simply add one to the other and I think when I do you will be very impressed so let's see if you are here we go okay so I'll be impressed how about no magic now then this is actually more physics in chemistry what we have here is a water container which has had the bottom cutoff and a bit of plastic sheet put on and that is because there's a bungee cord inside I can see you're not particularly impressed with what I just shown you however it can become quite impressive if you use some smoke in it because if you've got smoking it you can do this [Applause] these these things to use the physics term are called toroidal vortices we probably know them better as smoke rings and basically the way they form all this does is effectively push out a ball of smoke but the ball is smoked as it goes through the air basically it can you see the the air basically kind of causes the outside of the smoke ball to kind of turn around and in on itself as it comes obviously and resists it another is what causes the smoker in the form so probably as I say more physics in chemistry but still see and I think okay now that let me show you this reaction here okay this reactions uses just got a little bit of powder here when I teach the chemistry of metals and we talk about different metals having different reactivities one of the things that I show is a displacement reaction where a more reactive metal can actually displace a less reactive one from a compound that's a mixture of magnesium and silver nitrate and magnesium is much more reactive in silver nitrate but they can't react until they both solids and to solids can't get at each other so effectively they can only react when one of them is dissolved once the silver nitrate so we need some water and we've got some water we have the lights down please for this I gotta try and hit that Oh especially with the lights off maybe okay I'm gonna show you that one again you probably can't see too much if you just look at that one but basically magnesium burns the pretty bright white flame and if you to be used in the olden days in flash photography these days we use electronic flashes obviously instead but it still has using things like fireworks and distress flares things like that okay could be the lights done but not quite as much as last that's perfect great thank you very much oh the reason I'm showing this again is because there's a slight difference this time I've added another chemical just a tiny little bit of another chemical I'm not chemical just happens to be heat sensitive ready now we haven't yeah okay can you actually see me at all at the moment cuz all I can see is a big green blob and for in my eyes basically so okay we've got same balloon as we started with but this time I've added something else to it and I got two more here now they are all filled with hydrogen but I've also put a couple of chemicals in them same as firework manufacturers do one of them has got a lithium compound in one of them has got a sodium component and one of those got a barium compound in and they give reds yellows and green colors to flames fireworks use them all the time so when the hydrogen flame goes this time then we are gonna see hopefully a better color as well okay let's get our light out I'm not quite sure which is which because they all look exactly the same but one should be red one yellow and one green okay right let's see which ones first actually we run a bit short of time so you know it speed things up a little bit oh by the way when the hydrogen burns like any flame it has to use oxygen and that's obviously in the air around but effectively the hydrogen can only burn when the oxygen outside allows it to I'm just wondering all might happen if we put the oxygen in the balloon with it anybody interested in that shall we maybe try that what's wrong okay here we go this one has got oxygen in as well and now we are ready for action okay can I have the lights down please for this one thank you very much okay guys ready here we go my shoe Oh - didn't go hang on let's get them to close together rather there we go try again the last - oh and it still didn't go okay well unfortunately they're going on their own but they're going whether they like it or not okay this one because it's got the oxygen already in it so you should be okay out there worried about me here here we go guys [Applause] thank you very much I hope you had the fun I certainly did anyway [Applause]

Channel: TEDx Talks

Views: 171,193

Rating: 4.5147338 out of 5

Keywords: TEDxTalks, English, Science (hard), Chemistry, Teaching, Youth

Id: gbyOFF-eC-Q

Length: 11min 57sec (717 seconds)

Published: Tue Nov 20 2018