Name: オクテットルールの例外｜AP化学｜カーンアカデミー (Exceptions to the octet rule | AP Chemistry | Khan Academy)
Uploaded: 2021-01-14T10:33:56.000Z
Duration: 7 min 10 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：

- [Instructor] In this video, we're gonna start talking

which we've talked about in many other videos.

that they're able to have a full outer shell.

They're able to have eight valence electrons.

Now, we've already talked about some exceptions,

But as we'll see, there are other exceptions.

they can form stable molecules where the boron

or the aluminum only have six valence electrons, not eight.

And there are exceptions in the other direction.

As you get to the third period and beyond,

we'll actually see atoms that can maintain more

And we're actually going to see an example

see if you can come up with the Lewis diagram

See if you can draw the Lewis diagram for that.

So the first thing you wanna do is account

Aluminum's outer shell is the third shell,

and it has one, two, three valence electrons.

and each hydrogen has one valence electron.

three plus three is equal to six valence electrons

to try to draw the structure with some covalent bonds.

We don't wanna make hydrogen our central atom.

And then we're gonna have three hydrogens.

And then let's put some covalent bonds in here.

And so let's see, how many valence electrons

So we have just accounted for all six valence electrons.

So we have no more valence electrons to play with.

Let's think about how the various atoms are doing.

So the hydrogens are all meeting their duet rule.

These two electrons in this bond are hanging around hydrogen

But from hydrogen's point of view, it has a full duet,

that hydrogen as well and that hydrogen as well.

valence electrons around it, and so it's not a full octet.

But aluminum hydride is actually something

if you can draw the Lewis diagram for this.

on introduction to drawing Lewis diagrams.

So xenon right over here, it's actually a noble gas.

It already has a full octet in its outer shell,

And then fluorine, we've seen this multiple times,

seven valence electrons, but there's five of them.

I'm gonna be drawing a lot of electrons in this.

So this gives us a total of eight plus 35,

So we have to take one electron away because of that.

So let's take away one valence electron to get that cation.

So the next step is to try to draw its structure

And xenon would be our preferred central atom

字幕リスト動画再生

オクテットルールの例外｜AP化学｜カーンアカデミー (Exceptions to the octet rule | AP Chemistry | Khan Academy)

specific

multiple

debate

controversial