Answered by Visakan Veerasamy

Visakan Veerasamy的回复：

I take inspiration from this chemistry professor:

这位化学教授的故事让我很受启发：

SARAH: Daddy, were you in the shower?
DAD: Yes, I was in the shower.
SARAH: Why?

萨拉：爸爸，你刚刚在洗澡吗？
爸爸：是呀，我刚在洗澡。
萨拉：为什么？

DAD: I was dirty. The shower gets me clean.
SARAH: Why?
DAD: Why does the shower get me clean?
SARAH: Yes.

爸爸：我身上很脏。洗澡能让我变干净。
萨拉：为什么？
爸爸：你是问为什么洗澡能让我变干净？
萨拉：嗯。

DAD: Because the water washes the dirt away when I use soap.
SARAH: Why?
DAD: Why do I use soap?
SARAH: Yes.

爸爸：因为如果我用肥皂的话，水就能把脏东西冲走。
萨拉：为什么？
爸爸：你是问为什么我要用肥皂？
萨拉：嗯。

DAD: Because the soap grabs the dirt and lets the water wash it off.
SARAH: Why?
DAD: Why does the soap grab the dirt?
SARAH: Yes.

爸爸：因为香皂能抓住脏东西，然后让水把它们冲走。
萨拉：为什么？
爸爸：你是问为什么肥皂能抓住脏东西？
萨拉：嗯。

DAD: Because soap is a surfactant.
SARAH: Why?
DAD: Why is soap a surfactant?
SARAH: Yes.

爸爸：因为香皂是一种表面活性剂。
萨拉：为什么？
爸爸：你是问为什么肥皂是一种表面活性剂？
萨拉：嗯。

DAD: That is an EXCELLENT question. Soap is a surfactant because it forms water-soluble micelles that trap the otherwise insoluble dirt and oil particles.
SARAH: Why?
DAD: Why does soap form micelles?
SARAH: Yes.

爸爸：这个问题问得真棒！肥皂之所以是一种表面活性剂，是因为它能形成一种水溶性的胶束，这种胶束可以抓住其他不可溶的污垢和油粒子。
萨拉：为什么？
爸爸：你是问为什么肥皂能形成胶束？
萨拉：嗯。

DAD: Soap molecules are long chains with a polar, hydrophilic head and a non-polar, hydrophobic tail. Can you say ‘hydrophilic’?
SARAH: Aidrofawwic
DAD: And can you say ‘hydrophobic’?
SARAH: Aidrofawwic

爸爸：肥皂分子是由一个极性的亲水基和一个非极性的疏水基构成的长链。你会说“亲水”这个词吗？
萨拉：轻岁。
爸爸：那你会说“疏水”这个词吗？
萨拉：苏岁。

DAD: Excellent! The word ‘hydrophobic’ means that it avoids water.
SARAH: Why?
DAD: Why does it mean that?
SARAH: Yes.

爸爸：太棒啦！疏水的意思就是防水。
萨拉：为什么？
爸爸：你是问为什么是这个意思？
萨拉：嗯。

DAD: It’s Greek! ‘Hydro’ means water and ‘phobic’ means ‘fear of’. ‘Phobos’ is fear. So ‘hydrophobic’ means ‘afraid of water’.
SARAH: Like a monster?
DAD: You mean, like being afraid of a monster?
SARAH: Yes.
DAD: A scary monster, sure. If you were afraid of a monster, a Greek person would say you were gorgophobic.

爸爸：这是希腊语！“Hydro”的意思是水，“phobic”的意思是“害怕的”。“Phobos”就是害怕。所以“hydrophobic”的意思就是“怕水”。
萨拉：像怪兽那样?
爸爸：你是说，像害怕怪兽那样？
萨拉：嗯。
爸爸：是啊，是个可怕的怪兽。如果你害怕怪兽，希腊人就会说你是“疏怪兽的”。

(pause)

（停了一会儿）

SARAH: (rolls her eyes) I thought we were talking about soap.
DAD: We are talking about soap.

萨拉：（转了转眼珠）我以为我们在讨论肥皂。
爸爸：我们是在讨论肥皂呀。

(longish pause)

（停了好一会儿）

SARAH: Why?
DAD: Why do the molecules have a hydrophilic head and a hydrophobic tail?
SARAH: Yes.

萨拉：为什么？
爸爸：你是问为什么肥皂分子有一个亲水端和一个疏水端？
萨拉：嗯。

DAD: Because the C-O bonds in the head are highly polar, and the C-H bonds in the tail are effectively non-polar.
SARAH: Why?

爸爸：因为端部的碳氧键极性强，尾部的碳氢键完全非极性。
萨拉：为什么？

DAD: Because while carbon and hydrogen have almost the same electronegativity, oxygen is far more electronegative, thereby polarizing the C-O bonds.
SARAH: Why?

爸爸：因为碳和氢电负性几乎相同，而氧的电负性更强，所以碳氧键有极性。
萨拉：为什么？

DAD: Why is oxygen more electronegative than carbon and hydrogen?
SARAH: Yes.

爸爸：你是问为什么氧的电负性强于碳和氢？
萨拉：嗯。

DAD: That’s complicated. There are different answers to that question, depending on whether you’re talking about the Pauling or Mulliken electronegativity scales. The Pauling scale is based on homo- versus heteronuclear bond strength differences, while the Mulliken scale is based on the atomic properties of electron affinity and ionization energy. But it really all comes down to effective nuclear charge. The valence electrons in an oxygen atom have a lower energy than those of a carbon atom, and electrons shared between them are held more tightly to the oxygen, because electrons in an oxygen atom experience a greater nuclear charge and therefore a stronger attraction to the atomic nucleus! Cool, huh?

爸爸：那就复杂了。对于这个问题有多种解释，取决于你采用的是鲍林标度还是密立根标度。鲍林标度的原理在于，在某一元素作为基准的条件下，通过计算不同元素的分子与其键能之差从而计算出相对电负性。而密利肯尺度是基于电子本身亲和能和电离能的性质。但最终还是归结于有效核电荷数。氧原子的价电子能较碳原子价电子能低，两者之间的共用电子会被氧紧紧束缚，因为氧原子内的电子受到了更强的核电荷作用，所以会被原子核强吸引！酷吧？

(pause)

（停了一会儿）

SARAH: I don’t get it.
DAD: That’s OK. Neither do most of my students.

萨拉：我没听懂。
爸爸：没关系。我的大部分学生也不懂。

EDIT: Here's the original source: A DIALOGUE WITH SARAH, AGED 3: IN WHICH IT IS SHOWN THAT IF YOUR DAD IS A CHEMISTRY PROFESSOR, ASKING “WHY” CAN BE DANGEROUS

补充：以下是原文链接：与三岁的Sarah的对话：如果你爸爸是化学教授，追问“为什么”后果可能会很严重哦

About Stephen McNeil

关于Stephen McNeil

Stephen McNeil is an Assistant Professor of Chemistry at the University of British Columbia Okanagan in Kelowna, British Columbia. To date, he has been interviewed on the radio four times: twice he was talking about chemistry, and twice he was talking about pirates. His favourite element is the element of surprise.

Stephen McNeil是一名化学助理教授，就职于不列颠哥伦比亚省基隆拿市的英属哥伦比亚大学（University of British Columbia）欧垦那根校区。迄今为止，他一共接受过四次电台访问：两次聊的是化学，另外两次聊的是海盗。他最喜欢的元素是the element of surprise（注1）。

注1：这句话里的element是双关，element有元素的意思，element of surprise 指出其不意，不是指自己被惊喜，而是说自己具备出人意料的优势。