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  • Uhm.

  • Excuse me.

  • Pardon me.

  • No, no no. Not up there.

  • I'm down here.

  • Yup.

  • Hello!

  • I am a scientist. And I've come to improve your situation just a bit.

  • See that fire over there?

  • Have you ever really wondered what the flames are from that fire? I mean look at all of those colors.

  • And you feel that heat. It's hot, right?

  • Well gee, it must be torture being around all these flames and not knowing what they are.

  • Here, take a look at this cupcake.

  • You see a flame on top of this delicious looking cupcake?

  • You do like cupcakes, don't you?

  • Let's take a closer look, shall we?

  • Fantastic!

  • If we look at the flame on top of this cupcake, we first notice a few things, like all the colors

  • At the bottom, we have this blue-ish color.

  • On the top, it's more yellow, orange, redish.

  • Also the flame is hot.

  • Why is it so flaming hot?

  • Well, to answer these questions, you need to know something very important.

  • You see everything is made up of tiny things

  • called atoms. And these things are the building

  • blocks that make up everything!

  • And they're really small.

  • Smaller.

  • Smaller!

  • Even smaller!

  • Hey, look, you can't even see

  • them, they're so small.

  • Exactly!

  • Anything you can think of is made up of atoms.

  • Yup, this air condition is made up of atoms.

  • This delicious popsicle is made up of atoms.

  • This ice water is made up of atoms.

  • Everything is made up of billions and billions of atoms.

  • Now, this candle and flame are made up of three kinds of atoms

  • carbon, hydrogen, and oxygen.

  • The carbon and the hydrogen are locked together

  • to form the solid wax and wick.

  • The oxygen is a gas all around us.

  • Normally, the oxygen doesn't do much to the candle

  • It just bounces off of the surface, not doing any real damage.

  • But when we add heat, the oxygen

  • atoms go bananas!

  • And they shake the wax, like crazy!

  • Until finally, with enough force, they snap apart.

  • They leave the candle as a gas.

  • where they mix with the oxygen.

  • Uh oh, I smell trouble.

  • Well the fancy science word for all of this is

  • pyrolysis.

  • It is the first thing that needs to happen to get a flame.

  • It's when the fuel turns to a gas.

  • Now let's see what happens when these hot gasses combine.

  • Announcer: Ladies and gentlemen, in this corner

  • he was once a solid, now he's a gas. He's the fuel from the West!

  • And in this corner, not one, but two groups of oxygen

  • Ready?

  • React!

  • Narrator: Any time certain atoms get hit hard enough,

  • they spit out blue light.

  • And because there are lots of atoms getting hit hard

  • and lots of atoms spitting out blue light

  • we get a blue flame.

  • Here comes another science word. Ready?

  • Chemiluminescence.

  • I know, it's a big one.

  • One more time.

  • Chemiluminescence.

  • It's when atoms shine light

  • when they rearrange.

  • It's why flames are blue

  • Now the blue light is not hot.

  • Wait!

  • But the blue flame is really hot!

  • So if the blue light is not the hot part,

  • then what does make a flame so hot?

  • Well, remember our fuel atom?

  • and our oxygen atoms?

  • They rearranged to make new stuff like water

  • and carbon dioxide.

  • And as they rearrange, they snap together.

  • And with each

  • snap

  • the new thing shakes like crazy!

  • So when the rearranging is done, we have

  • lots of new stuff

  • all shaking really fast!

  • If we put something close to those raging atoms

  • then those atoms begin shaking like crazy too,

  • like the atoms in our fingers -- that's heat.

  • This is called oxidation.

  • It's when the oxygen atoms combine with other atoms to make new stuff.

  • It's why flames are so hot.

  • Alright then, why are most flames

  • yellow, orange, red?

  • Well, remember our first reaction?

  • We had one group of fuel atoms and two groups of oxygen.

  • They made a flame that was very hot.

  • And only blue.

  • But watch what happens if there's not enough oxygen

  • and we take some away.

  • Announcer: Ladies and gentlemen what happens when there's

  • not enough oxygen?

  • audience gasp

  • Announcer: what's this? A single carbon atom left all alone!

  • Narrator: It's okay, because all of his left-over carbon

  • friends come to join him

  • and they form large, black particles we call soot.

  • Okay, they're not so large. They're so small

  • we can't even see them.

  • But to a single atom, they are enormouse!

  • Announcer: Enormous!

  • Narrator: I know what you're thinking.

  • How do black particles make yellow flames?

  • Well let me show you.

  • But first, I need something big and black

  • like this pitch fork.

  • Excuse me sir, Your Evilness,

  • could you please place your pitch fork in

  • those scorching flames? Thank you.

  • Big black objects are like sponges that soak up heat.

  • They have to get rid of this energy, so they spit it out

  • by glowing.

  • The hotter they get, the more brightly they glow.

  • Now the same thing happens with our soot particles.

  • They drink in heat from all those hot atoms.

  • And they glow brighter and brighter!

  • Until they look like this!

  • And because there are millions and millions of soot particles

  • all glowing hot

  • we get this yellow flame.

  • Audience: ooh!

  • This is called incandescence.

  • It's when the soot particles glow because they're hot.

  • it's the reason why flames are yellow.

  • Well, that's it. That's what flames are.

  • I mean, who knew cupcakes could be so much fun.

  • Remember, first the fuel loses mass and turns into a gas.

  • Before the next change is through, atoms shine blue.

  • When the process is complete, it gives off heat.

  • Extra carbon will grow red, orange, and yellow.

  • Hey, those are just like the lyrics from that

  • really awesome song about flames.

  • You know, the one that goes:

  • The fuel loses mass

  • it turns to gas.

  • Before the next change is through

  • some atoms shine blue.

  • When the process is complete

  • it gives off heat.

  • Extra carbon will glow

  • red, orange, yellow.

  • The fuel loses mass

  • it turns to a gas

  • Before the next change is through

  • some atoms turn blue.

  • When the process is complete

  • it gives off heat.

  • Extra carbon will glow

  • red, orange, yellow.

  • chorus repeats

  • vocal backing: Pyrolysis

  • Chemiluminescence

  • Oxidation

  • Incandescence

  • repeat

  • song finishes

Uhm.

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B1 中級

什麼是火焰? What is a Flame

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    VoiceTube 發佈於 2013 年 04 月 25 日
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