評論
打印
Hi, I'm Jessica
嗨，我是Jessica
And today I'm going to shed some light on a chemical demonstration
今天我要講的化學演示
I like to call "anatomy of a glow stick"
叫作"熒光棒解剖"
There are many different kinds of chemical reactions
化學反應有很多種
Some absorb energy and some release energy
有一些需要吸收能量，有一些則會釋放能量
Some release energy as heat and others as light
釋放能量的形式有時是熱，有時是光
and when a reaction produces light
當反應生成光時
the process is called chemiluminescence
這個過程就叫作化學發光
Let's watch MIT's Dr. John Dolhun
下面來看MIT的John Dolhun博士
his assistant Shannon
他的助手Shannon
and volunteers Sarah, Catherine, and Trevor
以及志愿者Sarah Catherine和Trevor
They're gonna show us some chemiluminescence at the Cambridge Science Festival
在劍橋科學節上演示化學發光
So not all reactions have this ability to produce lights
并非所有化學反應都能產生光
So we have to use some very special chemicals in order to do this
為了實現這個目的，需要非常特殊的化學試劑
And we have some light sticks that I broke apart here
這里我破開了一些熒光棒
If you guys just want to take these solutions
請你們拿著這些溶液
hold them carefully
小心拿著
And so in a light stick
熒光棒中
usually there's actually hydrogen peroxide
通常會有過氧化氫
and it oxidizes different chemicals --
它能氧化不同化學試劑
Please face the audience. That's cool
請對著觀眾，這很酷
and it'll oxidize different chemicals
它能氧化不同化學試劑
depending on what color you want to give a light
取決于你想要什么顏色的光
Alright, just pour one solution to the other. It doesn't matter which way
好，請將一種溶液倒入另外一種中，兩種方式都行
And there we go, okay
有了，很好
Beautiful, beautiful, alright
很美麗，很美麗，好
So in each of these, we have a different chemical that gets oxidized
這每一個反應中，都有不同化學試劑被氧化了
to give us a different color
從而得到了不同顏色
Alright, thank you guys so much
好，非常感謝你們
So how does a reaction produce light?
反應是如何發光的呢
Let's start with two molecules. Let's call them A and B
首先是兩種分子，分別記作A和B
They react to produce C and D
它們反應生成C和D
Energy that's produced in the reaction
反應中生成的能量
causes the electrons in D to become excited
導致D中的電子被激發
As the electrons relax back down, they give off energy as light
隨著電子返回基態，它們會以光的形式釋放能量
So basically chemical energy is transformed into light energy
化學能被轉化為了光能
