Polar & Non-Polar Molecules: Crash Course Chemistry #23

Molecules come in infinite varieties, so in order to help the complicated chemical world make a little more sense, we classify and categorize them. One of the most important of those classifications is whether a molecule is polar or non-polar, which describes a kind of symmetry - not just of the molecule, but of the charge. In this edition of Crash Course Chemistry, Hank comes out for Team Polar and describes why these molecules are so interesting to him.

You'll learn that molecules need to have both charge asymmetry and geometric asymmetry to be polar, and that charge asymmetry is caused by a difference in electronegativities. You'll also learn how to notate a dipole moment (or charge separation) of a molecule, the physical mechanism behind like dissolves like, and why water is so dang good at fostering life on Earth.

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!

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Table of Contents
Charge Asymmetry & Geometric Asymmetry 01:33
Difference in Electronegatives 01:49
Hank is Team Polar 00:33
Dipole Moment 03:49
Charge Separation of a Molecule 04:12
Like Dissolves Like 04:41
Water is Awesome 05:10

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[crashcourse]

There is an error in this video at 9:56, in the video we say "non-polar" but it should say "polar" The video script should say: "A molecule needs to have charge asymmetry and geometric asymmetry to be POLAR." Thank you to our audience for pointing this out!

[amandavitti]

Hank: "If electrons were teenage girls, flourine would be niall horan." 
Me: it all makes sense now...

[harrys_vodka]

I feel like if more chemistry teachers referenced one direction I would understand everything so much more

[saturnus]

1- says one direction
2- i think about them
3- i research about their break up
4- i finish my research
5- its time to go to sleep

[aimanbahrim]

Eminem: im the fastest rapper alive

Hank: hold my glasses

[ansa]

Imagine dumping a bucket of water on someone and they just ...dissolve

[thatweirdguywhostalkspeopl]

Let me sum it up so you can let it sink in:
Polar molecules:
-do not have symmetry in their chemical formula
-may be bonded with Hydrogen
Nonpolar molecules:
-Have symmetry in their chemical formula
-may be composed of only 1 element
-may only be composed of Hydrogen and Carbon

[jRh]

Wish I could learn as fast as he talks.

[mckenna]

Just STARTING to learn this... and this went SO fast - it was confusing. I think this is more for people who are SURE of a concept and just want to review before a test, than it is for those just learning about it and want to understand the concept from the beginning.
I'll be back after I'm SURE of the concept.

[ColonialFungus]

To those who are having trouble keeping up, (I am not making fun of I simply comment to offer advice), turning on the captions can help with absorbing all of the information. Also, get used to the fact that your not going to always get the concept the with the first explanation, (Especially with Chemistry and the b**ch particle, AKA the electron) and that is why the rewind feature should be used often. Another thing to remember is that this is meant to be an overview meant for consultation, not for in depth learning of the concept being taught in its entirety. I hope this helped.

[singinglips]

I came here to escape one direction and focus on my exam WTF YO

[hiarchie]

Killers: Using weapons
Me, an intellectual: *Dissolves my enemies with water*

[crashcourse]

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! 

[HighAnders]

too complicated, just gonna get that F tomorrow

[sashickgirl]

For those who struggle with the speed of him talking try setting up the speed at 0.5 in the settings on the bar below the video + the bonus of Hank sounding vaguely drunk

[crashcourse]

Accurate. Thanks Jan.
Sorry for the mix-up everyone, we will try to be more diligent in our proofing in the future.

[onedirectionandpercyjackso]

Here again I came here thinking of studying
And there's One Direction!Great wish me luck I have an exam.

[coleallen]

2:44 The two elements that are highlighted when talking about chlorine and bromine were not actually chlorine and bromine they were carbon and boron the symbol for chlorine is Cl bromine Br boron B and carbon C

[kashshk]

i love how hank mentions the boys in so many videos, you can try escaping but hank is the electron to the 1d atom that will attract u. SHOOK

[gustafson]

I actually like how he talks fast... It means I can learn more within a limited time space.