Name: 核だクラッシュコース化学 #1 (The Nucleus: Crash Course Chemistry #1)
Uploaded: 2021-01-14T05:37:32.000Z
Duration: 10 min 12 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Hello, I'm Hank Green and I want to teach you chemistry. But please,

do not run away screaming. If you give me five minutes to try to convince you that

転換語

the amazing and beautiful science of stuff. And if you give it a chance

it will not only blow your mind but also give you a deeper understanding of

your world. This is just my opinion here,

but I think that understanding the world leads to greater ability to enjoy the

world and there's nothing that helps you understand the world better than chemistry.

Chemistry holds the secrets to how life first formed, how cancers are cured, how

iPhones have bigger hard drives than 5 year old laptops

and how life on this planet might just be able to continue thriving,

even ours, if we play our cards right. Chemistry is the science of how three

tiny particles, the proton, the neutron and the electron

came together in trillions of combinations to form,

get this, everything. Now chemistry is a peculiar science, sometimes talked

about as a bridge between the ultra abstract world of particle physics and

But calling chemistry a bridge is like calling Eurasia an island.

Chemistry has it all, mad scientists, world changing revelations, the practical,

the impractical, medicine, bombs, food, beauty, destruction, life and death,

answers to questions you never knew you had.

I love chemistry, and I hope I can give you a glimpse into why.

So today, let's start out with maybe the biggest idea of all time, and move on

I know, you aren't shocked, you aren't awed, you might not even be paying attention any more,

but when atomic theory was first proposed, it sounded

pretty crazy. And yes, we call it 'Atomic Theory', using the scientific definition of theory,

which is "a well-tested set of ideas that explains many disparate

observations", not the colloquial definition of theory, which is

"a guess." But luckily there's no-one running around any more saying

"atoms are just a theory." But it wasn't that long ago that people were running around

saying that. You wanna know who settled it for good?

Einstein! Atoms had been postulated for a long time by the 20th century, but it

wasn't until Einstein mathematically proved the existence

of atoms and molecules in 1905 that the matter was truly settled.

And you thought Einstein was all about relativity and E=mc2, he also

proved atoms exist!  Here's how it happened. In 1827,

a botanist named Robert Brown was looking at pollen grains in water

that they jiggled randomly even when there was no movement to cause the jiggling.

It was a mystery for a long time, until 1905 when Einstein theorized that

this phenomenon was caused by as-yet-unproven

atomic particles actually smacking into the grains of pollen.

He wrote up some fancy math, showing that his theory predicted this motion almost perfectly,

and everyone had to concede that yes, tiny

discrete bits of matter were indeed smacking into the pollen,

and thus molecules, and by extension atoms, must exist.

Today, we remember this botanist and his discovery by calling the motion he observed

Brownian motion. It's kinda crazy that every physical thing you've ever

ball thingies. It started with people wondering what would happen if you just

Eventually, and of course it turns out that there's no knife sharp enough to do

pure, unbreakable bit of that substance. The word "atom",

indeed, is from the Greek for "indivisible", though, of course, as we learned in World War II,

atoms can be broken as well. So all the stuff that we think of as stuff

is made of atoms, tiny discrete particles that have specific properties depending

of three simple subatomic particles. There's the proton, heavy and positively

charged, the neutron, about the same size as the proton but neutral,

and the electron, which has the same amount of charge as the proton,

just opposite, and very nearly has no mass at all, about

1800 times less massive than the proton or neutron. Protons and

neutrons hang out in the nucleus, and thus are the nuclear components or nucleons;

electrons hang out around the nucleus and are the parts of the atom that do all

the interesting chemical stuff. But before we get to the chemistry of the

have got to understand the properties of the nucleus. Okay, this is pretty important,

so pay attention here. The number of protons in an atom

determines what element it is. 79 protons:

always gold. 59 protons: always praseodymium. The number of protons in an element

it sits right on top of the box in the periodic table because that is the

So an atom of silver with 47 protons in its nucleus is always an atom of silver.

Depending on what its electrons are doing and what it's bonded to, it might be

part of a chemical that's silver-colored or black or blue or shiny or poisonous

but whatever it is, that atom is still silver

and will remain an atom of silver probably forever,

because that core number is very, very difficult to change. Now you might have noticed something

weird about silver here: its chemical symbol, the one or two-letter short code

Silver, of course, because we've known about it for a long time, was one of the first

elements added to the periodic table, and back then

it was called "argentum", Latin for "shiny gray stuff",

also, the root of the word "Argentina", where Spanish explorers heard rumors

of mountains made of silver, which of course did not exist.

The name "Argentina", just like the chemical symbol

"Ag", stuck, despite neither of them being particularly representative

Nuclei, which is the plural of nucleus, are boring. They're thousands of times smaller than

the atom as a whole, and they mostly just sit around being exactly the same as

they were when they were first created billions of years ago,

held together by the strongest of the four fundamental forces of physics,