Valence Electrons

[Rind0Man]

I skip lectures to watch Khan Academy videos.

Thank you so much for the videos, really appreciate it!

[xXCorpseXPrincessXx]

=^-^= Sn is tin

<3

[Bakugantsuvai1]

What coincidence he actually used the color of Kryptonite I wonder if he is a superman fan.

[gokuandvegetass2]

lol pause at 3:24 for figures that look like pacman!! how this guy adds video game characters into chemistry i dunno! but it's a win!

[tstark05]

Sal, how on this great planet do you know so much?

[hodenboden]

Valence eletrons are not only those on the outer shell.

"The valence electrons are instead defined as those outside a noble-gas core"

(Wikipedia: wikipedia(dot)org/wiki/Valence­_electron)

[iamgig9876]

@hodenboden valence electrons are the shit in the outer orbitals which determine the shit that happens when the shit reacts, it also has a lot to do with covalent shit and the shit configurations.. understand the shit?

[jenlynnnnn1]

Sn is tin not selenium ....

[satisfiction]

Perhaps atoms want to have 8 electrons because of two per dimension. x,y,z,n ?

Striking a nice balance forming the outermost shell?

Hmmmmmmmm.......

[Mr4getitman]

Why do i feel im way better than all you?

[Breyerlov]

do you subtract the atomic number from the atomic mass to find the electrons?? how do you find the neutrons?

[monkeypenguinftw]

@Breyerlov correct me someone if im wrong, but i believe by subtracting the atomic number from the atomic mass you find the neutrons.this is because electrons are so small, they dont carry much weight.

[Breyerlov]

@monkeypenguinftw oh, ok, then how do you find the electrons??

[monkeypenguinftw]

@Breyerlov uhh well an electron is abt a.a6% of an atoms mass

[Breyerlov]

@monkeypenguinftw oh ok :)

[alo0oni333]

@Breyerlov mass- atomic number .. you always subtract a smaller number from the bigger one ;)

[MediumNothinFull]

sn, tin

[MediumNothinFull]

around 6:27, did you have a fly near the mic?

[MediumNothinFull]

i hope you know how thankful i am and glad to find this on the internet

#8..it will have something to do with music too if ya know what i mean..

[MediumNothinFull]

shit i only learnt a little bit i thought i learned alot

[f4st1ll0]

please make some examples for the f-group, i don't get why Uranium has [Rn] 5f3 6d1 7s2 and Plutonium [Rn] 5f6 7s2. What happens with that 6d1 ? o.o

[calabarbean]

LOL !!!! You don't even know the name of the elements??? And you wanna teach us??

What a shame Khan...

[jumb0mumb0]

@calabarbean

Do us a favor and go back to sleep then!!

[calabarbean]

@jumb0mumb0 Go fuck yourself retarded :P

[jumb0mumb0]

@calabarbean

You don't even belong in a discussion for a video on chemistry. With your degree of intelligence and lack of a sophisticated vocabulary, you belong in a prison cell with all the other inmates who may show signs of attraction toward you! Or better yet, enslaved to a low paying job where the employees have nothing better to do than swear. Do us a favor and go back to sleep!

[calabarbean]

@jumb0mumb0 Told you retard: Don't mess with me ! I know way more chemistry than you do. I've searched this video for my 16 years old kid so he could learn sth. And it is instructive, however it is not acceptable for khan not to know the name of elements !!

So again: Go fuck yourself :P

[jumb0mumb0]

@calabarbean

"Don't mess with me!" I already did, idiot. If you were a bug, i'd dissect you into thousand different pieces you pathetic sack of shit.You are clueless about elementary science, let alone chemistry.

[eruptoin]

@jumb0mumb0 dude forget about him, he's clearly retarded...

[jumb0mumb0]

@eruptoin

Thanks! He started off criticizing Sal for not being able to name an element when he hasn't contributed a thing to Youtube so I told if he doesn't like these vids to go back to sleep and that's where the drama began.

[calabarbean]

Told ya ! Don't mess with me ! Are you aware what 100 mg of i.v D-tubocurarine can do to you? No you are not :) Search on google, perhaps you'll find out ;)

[tapper1808]

Do you have anything on quantum numbers and energy required to to move to another energy shell? I am studying Chemistry.

[cabheat]

haha tin haha

[72Fisk72]

@PINKmeUP67 It's 7 because the highest energy level is 4. [Ar]4s2 3d10 4p5

The 4s2 and the 4p5 add to 7.

That 3d10 portion is what he was talking about when he mentioned the back filling. Make sense?

[donsbarkingdogs3]

Finally, I am getting this. Thank you Dr. Khan!

[PINKmeUP67]

when i write an electron configuration in noble gases, how do i know how many valence electrons there are? for example [Ar] 4s2 3d10 4p5 has 7 valence electrons. how does that work?! wouldn't it be 17?

[rjan926285]

This video helped me so much thank you!

[MrHaponese]

thats a pretty flower you drew

[MsDance2live]

I don't understand how to write that stuff in the beginning. How do you determine those numbers and letters...like what are you looking at to know that?

[789123Y]

All halogens are greedy bastards.

[IamDrMalick]

Dear Prof. Khan, is it possible to write Fe as [Ca]3d6? or would it be better to write it as [Ar]4s23d6 since it shows that 4 is the highest energy shell?

[jbnshah]

lol "if you dont trust me.." Dear Khan we will believe anything you say

[NereticSC2]

would be n1 if you add numbers to the video, to see which video is the next etc.

[Hemouth]

hydrogen and helium are 2 happy elements :D

[fluxD613]

thank you so much! big help!

[haitiangirl122391]

but other than that the video was good lol

[haitiangirl122391]

Iron is Fe not F.

[Phatnaru0001]

is it possible for for the A metals to give take from the halogens under certain conditions? Does it go that way because fewer electrons are transferred that way, so it is easier?

[ligitcounterfit]

when you say the "electron gets larger" might you simply mean that it's orbital goes out further ?

[wooferpoofer]

@ligitcounterfit no he meant to say as the atom gets larger

[ephraimtorres]

Great

[nuzhatjabeen56]

please use a different color pointer because it really hard to follow , like make it bigger bolder and a bright color (red maybe) i just cant follow it

[neiljenkinson1]

Thanks for information

[livetodancexox]

YOU MAKE CHEMISTRY EASY!

[purpleleach1]

Doesn't HE (Helium) only have 2 valence electrons? This still makes it a noble gas and are those 2 valence electrons the only electrons in the helium particle?

[lochlord]

thanks mate!!!!! I've been stressing about how on earth to count valence electrons without drawing out the whole frikin chart which would be a waste of time in an exam, but you've shown me an easier way to count them! Thankyou again!

[Petro7]

you make everything make so much sense... throughout these visa i keep having "EUREKA!! moments"

[creativeCAabstract]

ahhh omg, the feeling i get, when you kinda rhetorically ask a question and i can actually answer it and follow along..ahhhh ily dude. life saver.

[shakagenghis]

When you point at the moon, you're not supposed to focus on your finger. I don't think a whole lot of people are poorly served by his accidentally calling tin selenium, you could call it Bartholomew if you want for the purposes of the lecture. This mistake does not effect the lesson at all.  Secondly, I have paid good amounts of good money to be taught by teachers that majorly suck. Khan rules AND is free!

[ninjaturtle205]

atoms are such wannabees

[4545454545asp]

damn, here in Ontario, Canada, we assume the Bohr model is correct all through grades 9 and 10, only to learn that it's invalid in grade 11. it's a confusing waste of time that could totally be replaced by the likes of this!! gotta love this channel

[IBMua]

10:40 it's Fe, not F ^.^

[MrBroski28]

3 minutes in and I realize this video is no place for a seventh grader haha

[Termin8trix]

How did you mess up Sn with Se, Sn is tin...i've been let down. I thought he knew it all =\

[mrarphaxad1]

@Termin8trix yeah, I caught that too. Slight difference between selenium and tin... It scares me to think of what else he is mistaken about. He does a good job overall, but he should probably check over his videos before posting them. Regardless, the video is a good refresher before taking a test.

[Dr8co1]

i would rather pay you to teach me than my greek professor here at my college...

[SuperGooseDog]

Sn is tin!!!!!!!

[MsMacAttack17]

This was ridiculously helpful, thank you

[MrHemantrocks]

i am a 6th grader and i can understand this very well because Sal is a very good explainer. Isn't this type of chemistry high school level?

[Bookerbass11]

I spent 18 hours straight last quarter listening to (mostly) your lectures. Well, cramming went awesome, and I did alright on the midterm, but due to a lack of lab attendance, I'm back again for your awesome videos. Just wanted to say thank you for being a life saver!

[angelrosiie]

I think this video is wrong. My understanding is that: Groups 1-8 are 1-8 valence electrons (ie, the group number), Group 9-11 have no general rule because "d" electrons may or may not participate, and Group 12-18 is group number minus 10. Tut tut.

[Denise89C]

I am addicted to your videos. Honestly, my tuition is wasted on my professor. The only way I am doing well in my chem class is because of you. Thank you so much for all your help!

[paulceltics]

you are my master!

[walterbrunswick]

You put F for Iron!? And Sn for Selenium!?!!?

You're a good teacher, but maybe you should review your table!

[Denise89C]

@walterbrunswick I think he was rushing through for Iron... and that's why he missed the e in Fe. He's going through these 15 minute max intervals, so he flies through all the material without enough time for checking if he's made little mistakes. Either way, the material is clear, so we should not get hung up on details as long as you understand what he's trying to say. If this was a classroom setting, someone would have shouted out "Fe for iron" and that would have been easily corrected =)

[trickytwinsta]

well thx to my hero here, ill get a B instead of a C tommorow!

[Kaine852]

LOL I think he referenced Superman...

[DominoChild]

what video should i watch before this one? I don't understand some of the material.

[AlderDragon]

@DominoChild Check out the khanacademy website and look for the chemistry videos.

[BoredScripter]

The electronic configuration for Helium should be 1s2 instead of the 2s1 in the video.

[avatarmaster101]

I'm in college chemistry taught by a doctor of chemistry and he was unable to explain this as clearly and simply in an hour and half of lecturing as this gentleman was able to do in this 15 min video. Proof that smart is not necessarily and indicator of whether or not someone should be teaching. Most of the kids in my class are failing for this reason, too bad your not my chemistry professor! Thank you for the video!

[avatarmaster101]

I'm in college chemistry taught by a doctor of chemistry and he was unable to explain this as clearly and simply as this 15 min video. Proof that smart is not necessarily and indicator of whether or not someone should be teaching. Most of the kids in my class are failing for this reason, too bad your not my chemistry professor! Thank you for the video!

[Giallorossi03]

lol "silinium" ...it's tin :)

[youztuber5000]

@Giallorossi03 He's so silly....

[levakz]

@Giallorossi03 you guys...the periodic table consist of elements that are named in Latin and Greek. Tin is the English notation for this element. But yeah, it is kinda funny =D

[jasonjonathanjeng]

@Giallorossi03 Lol "silinium".....it's Selenium :P

[voldemort1112]

He has such a sexy voice

[jirasakura]

wow i really love teachers who dont just explain everything but also add their own intuitions about the topic! I love you,Sensei khan!

[swimmer798]

THANK YOU!! you're videos really help. i'm in AP chem now... I watch these videos right before a test or when I don't understand a concept taught in class.

my teacher in regular chemistry taught us that it's a sin (Sn) to forget tin... :)

[alchemistgrl]

@swimmer798 haha, so did my teacher =P

[TomGardnerr]

4 people were'nt clever enough to understand this.

[frozenstrawbs]

enlightening

[Funkella]

Thank you so much for this, after listening to your lesson on the periodic table I am now understanding this better than having two science teachers explain this configuration.

[TJisagirl]

I am so going to Ace my final thank you so much!

[Mrjayjubear]

this is why youtube and the information age we are currently in are so cool.

education is now nearly free

[EvilMashimaroXX]

Sn: selenium?! XD

[CandyChristine17]

I love the fact that your voice isn't monotone like almost all of the other videos on YouTube...kept me focused!

[Randomtei]

Im saved!!!

[15777kevin]

love your videos and your a great teacher but Perrytwelve is right Sn is tin

[hero0fdarkthepker]

I wish you were my lecture teacher

[MrJas1991]

@hero0fdarkthepker

Me too

[RETEPIOHC517]

When 4 People said dislike they're actually saying "dis i like"

[Perrytwelve]

these videos are amazing, only thing is Sn is Tin ;)

[UserIsAnFBIAgent]

omg, ...

[mozartgenetics]

I studied Robotics Engineering for 5 years and never heard this explained better.

[neytiri365]

Mr. Khan, you are an inspiration to all mankind!!!

[ladiiisoulz]

dis is freakin awesome!!!! thank you sooooooooooooooooooooo much

[wwecrazy213]

hes wrong FE has 8 valance electrons

[spuogis]

now i have to correct you there is an eception Cu and Cr has 4s1 ;)

[freha89]

Wow. My Chem teacher sucks compared to this guy.

[xNOTORIOUSBIGx]

This guy is a life saver. Thank you jesus

[hackingtime88]

how does fe have the same electron configuration as Ar?

[vlur]

Very good video....

But why is Gold [Xe] 4f14 5d10 6s1

why not 6s2 (you showed, that all elements in B-group have 2 valence electrons) and from where do we get those numbers for f and d orbitals.

Thank you!

[vlur]

@vlur

to expand on that question

Ir is [Xe] 4f14 5d7 6s2

but Pt is [Xe] 4f14 5d9 6s1

why is Pt 5d9 not 5d8



[hwhhww]

THANK YOU FOR THIS VIDEO!!

[lifeDotGov]

i learned more in his 5 videos than in 3 semesters of chemistry.

[clemens2003]

Sal you said in this video that atoms are best paired up when there are 8 electrons on the outside? Does this in anyway to your knowledge, theory, fundamental ideas have any relation to our solar system only having 8 planets? Has this been researched or have any theories been formed?

Just something that crossed my mind today.

[Nomoreidsleft]

@clemens2003 The rule is a function of the nuclear size, and the distance of the outer shell to the nucleus. It's simply that 8 electrons in the outer shell is more stable. That's when all forces are in balance. (atomic, magnetic, strong, weak, gravity) For star systems, the distances are so great that only one force is involved, gravity. The orbiting bodies will configure for lowest energy state for gravity. Also the bodies are not uniform, like electrons, protons, and neutrons.

[MarvelsofaLifetime]

@clemens2003: Things as miniscule as electrons have absolutely zero relation to things as big as planets.

[culnet]

Copper has 1 valence electron in its outmost shell that is why it is a good conductor better recheck what you are describing

[Soulquarium]

This is tough to understand.

[josephina323]

@Soulquarium Not really, if you follow the series from the beginning.

[xDAZZE]

Sn is tin and K is potassium

[burgert10]

Why couldnt iron's electron configeration be written as [Ca]3d6?

[Komamura0]

@burgert10

Because Calcium isn't a noble gas...and the noble gasses are the only "happy" elements. Happy meaning they have 8 electrons and are steady, not wanting to share or give. other elements, such as calcium, 'need' to give/gain electrons in order to be "happy"

[yogesh6802]

come on don't confuse every one you dont know to explain chemistry orbitals in an atom you are confusing orbitals and shells

[girlicious102]

wow ur videos helppp soo much i was studying for my chem exam and i had forgotten everything and ur videos helpedd me alot!!!! Thanks a ton

[joeleb]

i noticed the K= sodium mistake as well. a little flub, but it's out in the open now.  great video. i learned a lot! (again.)

[xDAZZE]

Yup. Sn is tin.

[ZX9Rish]

LOL Sn is tin, you also kept pointing at potasium when you were saying sodium. 34 is selenium and i am sure you know that 11 is sodium.

[circlesarecrazy]

YOU ARE EPIC!!!!!

[joshlete]

This is really frustrating because I don't understand what the p and d shells are from the previous video. It's really confusing to start of with perfect spherical shells and then all of the sudden you have dumbbell shaped shells!!!!!

[ParrhesiaJoe]

I really like that he uses reason to describe the orbital clouds. This is the best explanation I have heard short of unification theory. Way better than public schooling :)

[rushianokun]

sal you are EPIC

[myonlynick]

6:40-7:...... i kida disagree.Looking P.table i would say Cr and Cu have ONE not two electrons in their outer shell.All the rest ,yes they do have 2 in te outer shell

[mattdobz]

we don't say valence electrons in Britain. Instead, when an atom goes beyond 1 shell, we say 2nd shell, 3rd, 4th, 5th and so on.

still a useful video, good job

[marklosextremus]

thats the more simple version you just havent learnt advanced yet

[onlyAerik]

8 electrons.. 8 cubes defining cartesian coordinates' domains in a 3-dimensional space...

[trickst4r]

Love your work! Thank you so much ;)

[GlobalCitizenOne]

I learned more in 15 minutes of this video than what i had learned in 2 week of Chem class...

This is really proof that the American education system needs an OVERHAUL.

[luistr01]

yes this is the magician's salman

[arbaces]

@GlobalCitizenOne I agree. Let's overhaul an entire nation's education system based on your anecdotal evidense.

[GlobalCitizenOne]

*evidence 

[noahnz]

@GlobalCitizenOne Is it? Sal is way better than average as a teacher. No way you could fill schools with teachers of the same quality.

[Luigi84289]

@GlobalCitizenOne They don't want you to learn anything. They want you to drop out and work at home depot or mcdonalds for your whole life. There shouldn't be such a thing as weed out courses. If you want to learn the professor should be able to help you one on one and should present multiple ways of learning and understanding the material. They need to be continually evaluated. 10 year = dumb. You should have multiple sources as well besides the book to use for references. You pay an assload

[elphaphoenix]

@GlobalCitizenOne maybe u weren't listening...... and came here cuz you were clowning around or day dreaming off in class. u need an overhaul...

[MrHemantrocks]

@GlobalCitizenOne you're right, because in the American education system we really don't learn anything. Most kids in my school have to study at home because teachers don't teach much at all. On Most American education systems, the teachers always let the students "play" most of the time

[Celerity2]

You're really great ! thanks you !

btw - you forgot to mention that helium doesn't infact have 8 electrons (it's written under 8)

also wrote that Cu Ag and Au would have 2 electrons in their outer shell although they actually have 1 since they give away 1 to fill their d shell.

But thanks alot !

[niso1093]

Great video. I liked it very much. More capturing then other professors I had to listen. The language is easy an not so boring. Thank u.

[jegedy]

wow , you my friend can be a very successful university teacher , you explain this things like an alien , u seem to be very smart :) , thanks a lot for sharing ur wisdom mate

[superkrups20056]

Sn is tin hahaha I love you Khan!

[ScientificIlliteracy]

K is not sodium, but this is still a great video series!

[interxavierxxx]

Yeah, it's potassium, but hey, everyone makes mistakes once in a while. I just wish videos like these were available back in the day.

[azjeff1971]

This is good...but I still have to write the shells out and make lines to remember which order they go in!

[AnyCR87]

awesome... thanks!!!

[theinversematrix]

you sad little bastard.

never know how or when to thank people, do you?

go burn in hell.

sal's the best!

[lundburgerr]

what's wrong with the video then??

[mysterybunny]

chikwin sound like a dumbass.