Name: 氡 - 視頻的週期表 (Radon - Periodic Table of Videos)
Uploaded: 2021-01-14T10:15:23.000Z
Duration: 9 min 53 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

程度副詞

We always think of these scientists in the past

And here he is sitting in his office thinking

"Hee hee I've made my competitor feel uncomfortable"

it makes science seem so much more exciting.

We're in the library of the Royal Society

emitting an alpha particle - that's a nucleus of Helium

Radon is itself radioactive and decays so

you have to have it, as it were, freshly made. Rather like

you can only get fresh meat. If you keep it for a long

The half life of the most stable isotope of Radon

is just over three days so it's really relatively

short lived. That means if you have a certain amount of

gas, after three days you'll only have half of it.

And by the time you come back from your holidays

In the days that this letter was written,

the decay of Radium. In fact I've read - and this is quite

exciting. It's the first time you've ever seen a glass

in the library because they're strictly forbidden. -

The way they did it was to take a glass vessel

Imagine now you have a container of water with a

It is breaking down, generating Radon gas

very small amounts of gas, bacause Radium

Rutherford and Ramsay are really competing to get

And because it also contains alpha particles,

You've got to realize that these famous scientists

And so there was a sort of competition which is

And in fact Rutherford was really rude about

Ramsay's work. He says, his work - that's Ramsay's

work - is all right superficially, on the surface,

but when you get down in it you begin to see

the nothingness of it all. So he thinks it's rubbish.

So this is in a private letter to his friend Schuster -

"My dear Schuster", because in those days you called

your friends by their surnames. No first names;

is because he's real excited he has got a spectrum

It wasn't called Radon then; It was called

Radium Emanation - Emanation means "coming out

And he's got a spectrum, and Ramsay hasn't.

and he said, "Some of the lines run together

in the reproduction" - that's the print - "

and ??? they're quite clear in the negative"

So, he had an experiment in which he had a small

of a cubic centimeter, so it's not very much, in which

presumably, though he doesn't say so, he put

an electric discharge through it so that the gas glowed.

Rather like a Neon sign glows red in a shopping center.

And he then photographed this light coming out

with a photographic film, using a spectroscope to

All these gases give a whole series of lines

because you get a negative in the pho... originally

If you come close you can see it says the

At the top and the bottom are the spectra of

Helium gas as a calibration so that he can see

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氡 - 視頻的週期表 (Radon - Periodic Table of Videos)

realize

negative

spectrum

enthusiasm