Other Periodic Table Trends Khan Academy English (auto-generated) English

Other Periodic Table TrendsYouTube↗ IA↗(long shot)
Education 450.3K views 1.4K likes 39 dislikes 26 Aug 2009

Khan Academy 9.4M subscribers United States YouTube↗

Click to Play Video

in the last video we talked about

ionization energy or the energy required

In the last video we talked about ionization energy, or

to remove an electron and we saw the

the energy required to remove an electron.

general trend in the periodic table that

And we saw the general trend in the periodic table, that

you know when you're in the bottom

when you're in the bottom left-hand side close to

left-hand side close to cesium cesium really wants to give up electrons it's a

cesium, cesium really wants to give up electrons.

big atom it only has one extra electron

It's a big atom.

and it's six shell it can just give it

It only has one extra electron in its sixth shell.

up and then it'll have five complete

It can just give it up, and then it'll have

shells so it really wants to give it

five complete shells.

away so it requires very little energy

So it really wants to give it away, so it requires very

to ionize on their complete other side of the spectrum helium helium requires a

little energy to ionize. On the complete other side of the spectrum, helium requires

lot of energy to ionize it's very happy

a lot of energy to ionize.

it has a full shell at the first shell

It's very happy. I has a full shell at the first shell.

it's a very small atom the electrons are

It's a very small atom.

very close to the protons so the Coulomb

The electrons are very close to the protons.

force is super duper duper strong so it

So the coulomb force is super-duper-duper strong.

takes a lot of energy to remove that

So it takes a lot of energy to remove that incremental

increment electron we learned that and

electron, and we learned that.

the one thing I want to cover before

And the one thing I want to cover before moving on to

moving on to other types of trends or

other types of trends or properties amongst the

properties amongst the different atoms is the idea of a second ionization

different atoms is the idea of a second ionization energy.

energy second ionization second ionization energy now I do this because

sometimes it's covered on some chemistry

And I want to do this because sometimes it's covered on some

exams or some chemistry standardized

chemistry exams or some chemistry standardized tests.

tests and it's just the idea the

And it's just the idea that ionization energy is the

ionization energy is the energy required to remove the first electron to go from

energy required to remove the first electron, to go from a

a neutral state to take you popping one off one electron off of it the second

neutral state to popping one electron off of it.

ionization energy is then the energy

The second ionization energy is, then, the energy required

required to remove the very next

to remove the very next electron.

electron and the reason why this is

And the reason why this is interesting, is sometimes

interesting is sometimes you'll say okay you know with what elements have a very

they'll say, OK, what elements have a very high second

high second ionization energy and your

ionization energy?

your temptation would be okay high

And your temptation would be, OK, high ionization energy,

ionization energy that also probably means high second ionization energy and

that also probably means high second ionization energy.

that might be true for example neon has a very high ionization energy really

And that might be true. For example, neon has a very high ionization energy, It

wants to keep that tenth electron because it fills out the the second

really wants to keep that 10th electron, because it fills out

shell and then of course even at if you

the second shell. And then, of course, even if you were able to remove that

were able to remove that electron to remove the the ninth electron when you

electron, to remove the ninth electron, when now its

know now it's configuration looks a lot

configuration looks a lot like fluorine,

like fluorine that's still very

that's still very difficult.

difficult so you'd say it's second

So you'd say its second ionization energy

ionization energy is still very high but

is still very high.

if you think about it the elements with the second the elements with the highest

But if you think about it, the elements with the highest

second ionization energy

second ionization energies are going to be some of the

are going to be some of the elements with the lowest ionization energy so

elements with the lowest ionization energy.

think about it and they might be kind of

So, think about it.

confusing and let me say lithium lithium

And that might be kind of confusing.

for example very low ionization energies

Lithium, for example. Very low ionization energy.

got that little extra electron it just

It's got that extra electron.

wants to give it away but once it gives

It just wants to give it away.

it away it's in a very stable situation

But once it gives it away, it's in a very stable

then its electron configuration looks

situation, Then its electron

like helium so to remove that second

configuration looks like helium.

electron is super duper duper difficult

So to remove that second electron is super-duper-duper difficult.

so lithium has a very high second

So lithium has a very high second ionization energy.

ionization energy and so you might run into a question where they're like you

And so you might run into a question where they're like,

know what which of these elements has the biggest difference between their

which of these elements has the biggest difference between

their ionization energy and their second

their ionization energy and their second ionization

ionization energy or their second

energy, where their second ionization energy is higher

ionization energy is higher than their

than their ionization energy.

ionization energy and lithium or anything in Group one that would be true

And lithium, or anything in group one, that would be true,

because as soon as you remove one

because as soon as you remove one electron, its electron

electron its electron configuration becomes super stable so removing that

configuration becomes super stable, so removing that

second one is super duper difficult and

second one is super-duper difficult.

you also see this in this chart this is

And you also see this in this chart.

of course the first ionization energies

This is, of course, the first ionization energies.

but let's say the case with lithium you

But let's say, the case with lithium, you

remove that electron it was very easy

removed that electron.

you only needed five electron volts to

It was very easy. You only needed five electron volts to do it.

do it but then your configuration looks

But then your configuration looks a lot like helium.

a lot like helium so that second

So that second ionization energy is going to look a lot

ionization energy is going to look a lot like helium's first ionization energy

like helium's first ionization energy.

anyway don't want to confuse you too

Anyway, I don't want to confuse you too much.

much but that's an interesting point

But that's an interesting point that might pop up every

that might pop up every now and then now

another property which is in a lot of

Now another property, which is in a lot of ways, in my mind,

ways in my mind related is the idea of

related is the idea of electronegativity.

electro negativity electro negativity

concept came up with by Linus Pauling I

The concept came up by Linus Pauling.

always remember him is he was convinced

I always remember him.

that vitamin E a famous chemist and you know but his what I always remember is

He was a famous chemist. What I always remember is that he

that he was famous for being convinced

was famous for being convinced that Vitamin C was kind of the

that vitamin C was kind of the key to

key to living forever.

living forever and he would take huge doses of vitamin C I should probably

And he would take huge doses of Vitamin C.

read up on that again I don't want to

I should probably read up on that again.

spread lies about Linus Pauling but I

I don't want to spread lies about Linus Pauling.

remember reading that when I was in high

But I remember reading that when I was in high school.

school but anyway he came up with the idea of electronegativity and the idea

But anyway, he came up with the idea of electronegativity.

is that the one two atoms form covalent

And the idea is that when two atoms form covalent bonds--

bonds and I haven't cover haven't taught you what a covalent bond is so and I was

and I haven't taught you what a covalent bond is, and I was

planning on doing that in in a couple of videos from now covalent bond but the

planning on doing that in a couple of videos from now--

idea of a covalent bond is really just

but the idea of a covalent bond is really just atoms

atoms sharing electrons let me draw that

sharing electrons.

out so if I have oxygen oxygen looks something like this I could draw it like that I

Let me draw that out. So if I have oxygen, oxygen looks something like this.

could also draw oxygen like this just

I could draw it like that. I could also draw oxygen like this, just because I'm going

because I'm going to use these extra

to use these extra electrons to bond.

electrons to bond and it should take Elektra oxygen like that you you add it

And if you take oxygen like that and you add it to two

to two hydrogen's hydrogen has one

hydrogens-- hydrogen has one electron--

electron what's going to happen well you

what's going to happen?

might not know yet if you haven't seen a

You might not know yet, if you haven't seen a covalent bond.

covalent bond but the atoms will actually share electrons so this oxygen

But the atoms will actually share electrons.

you put it in the center you have these

So this oxygen, you put it in the center. You have these, over here.

over here let me draw it like that so the oxygen I'll do it in green the

Let me draw it like that.

electrons from oxygen I'll do in green

The electrons from oxygen I'll do in green.

and then in hydrogen hydrogen well I'll

And then hydrogen, I'll just do it in this orange color.

just do it in this orange color so we have two of these hydrogen's so one

So we have two of these hydrogens.

hydrogen will be there and then the

So one hydrogen will be there.

other hydrogen will be there now what

And then the other hydrogen will be there.

just happened well if this hydrogen if

Now what just happened?

this hydrogen can pretend that both of

Well if this hydrogen can pretend that both of these

these electrons it has to kind of share

electrons, it has to kind of share this green

this green room with the oxygen and the

one with the oxygen.

deal is hey I share the green one and you know you let me borrow the green

And the deal is, hey, I share the green one and you let me

room and I'll let you borrow the orange

borrow the green one, and I'll let you borrow the orange one,

one we both can kind of feel like we

we both can kind of feel like we have a stable electron

have a stable electron configuration

hydrogen feels good because the 1s shell

Hydrogen feels good because the one s-shell

is completely filled oxygen feels great

is completely filled.

because it's its valence shell is

Oxygen fills great because it's valence shell is

completely filled with eight electrons

completely filled with eight electrons, two

you know two of which are barred so it

of which are borrowed.

feels great this is a covalent bond

So it feels great.

where where the atoms are sharing

This is a covalent bond, where the

electrons and so this is sometimes will

atoms are sharing electrons.

be drawn like this oxygen those are the

And so this sometimes will be drawn like this. Oxygen.

extra electron pairs of oxygen and

Those are the extra electron pairs of oxygen.

they'll just draw a line like that a

And they'll just draw a line like that.

line like that and these that line

implicitly is saying look there's two

And that line implicitly is saying, look, there's two

atoms on either end you know there's the

atoms on either end.

oxygen atom I'm gonna saw the electron the oxygen electron there and then you

There's the oxygen electron there.

have the hydrogen electron there and

And then you have the hydrogen electron there.

they're kind of shared these two things

And they're kind of shared.

mean the same thing but that but that

These two things mean the same thing.

line just means a covalent bond now my

But that line just means a covalent bond.

whole point behind talking about

Now my whole point behind talking about covalent bonds a

covalent bonds a little prematurely so that I can touch on electronegativity

little prematurely is so that I can touch on

and the idea that Linus Pauling came up with is that in these covalent bonds the sharing is not equal that some of the

electronegativity. And the idea that Linus Pauling came up with is that in these covalent bonds, the sharing is not equal.

elect some of the atoms will hog the

That some of the atoms will hog the

electrons a little more so in this case

electrons a little more.

oxygen I mean we learn

So in this case, oxygen.

about oxygen oxygen oxygens way over

We learned about oxygen.

here it loves to grab electrons because

Oxygen is way over here. It loves to grab electrons.

it's way you know it's it has a very high ionization energy it's you know

It has a very high ionization energy.

it's only two away from having an

It's only two away from having an electron configuration

electron configuration similar to neon and being super duper happy so oxygen

similar to neon and being super-duper happy.

loves electrons hydrogen's a little bit

So oxygen loves electrons.

here there could gain electron and then

Hydrogen is a little bit here or there.

it'll be it'll have a stable 1s orbital

It could gain an electron and then it'll have a stable 1s orbital.

or it can lose an electron and a little

Or it could lose an electron and it will essentially just

centrally just turn into a positive ion

turn into a positive ion.

it can go either way so it's a little

It can go either way.

bit more ambivalent about which you know what what what it does what happens

So it's a little bit more ambivalent about what happens

relative to the electrons but oxygen

relative to the electrons.

really wants the electrons so that it

But oxygen really wants the electrons so

can get completed

that it can get completed.

so in this relationship between oxygen

So in this relationship between oxygen and hydrogen,

and hydrogen oxygen is more electronegative it's more

oxygen is more electronegative.

electronegative which means it kind of

It's more electronegative, which means it kind of hogs

hogs the electrons a little bit more so

the electrons a little bit more.

if you were to draw this this relationship here it might look

So if you were to draw this relationship here, it might

something you know if you were to draw this this bond and you know this is all

look something-- If you were to draw this bond.

abstract and you know maybe you would

This is all abstract.

draw it that it would be a little bit

Maybe you would draw it a little bit

heavier on that side and this is not

heavier on that side.

really at all a convention but I just

And this is not really at all a convention, but I

made that up or if you just drew thee

just made that up.

just say the the hydrogen and the oxygen

Or if you just drew the hydrogen and the oxygen part

part of it maybe you know the electrons

of it, maybe the electrons spend most of their time

spend most of their time around if this is a probability distribution and less

around-- this is a probability distribution-- and less of

of their time around hydrogen and that

their time around hydrogen.

would be the true that would be true for

And that would be true for the other hydrogen.

the other hydrogen they spend less of

They spend less of their time around the hydrogen and a lot

their time around the hydrogen a lot more of their time around the oxygen the

more of their time around the oxygen.

idea of electronegativity is just that

The idea of electronegativity is just that one atom is going

one atom is going to hog the add of the electrons more when you form a covalent

to hog the electrons more when you form a covalent bond.

bond now if we wanted to figure out the trend of electronegativity on the

Now if we wanted to figure out the trend of electronegativity

periodic table what do you think is going to happen which out which elements

on the periodic table, what do you think's going to happen?

are likely to hog electrons well the

Which elements are likely to hog electrons?

ones that love electrons the ones that

Well, the ones that love electrons.

it's very hard to take electrons away

The ones that it's very hard to take

from them the ones that are so close to compose to completing their there they're a full full eight valence

electrons away from them. The ones that are super-close to completing a full eight

electrons in their outermost shell so

valence electrons in their outermost shell.

the most electronegative atoms are going

So the most electronegative atoms are

to be right here they're going to be

going to be right here.

they're going to be the halogens

They're going to be the halogens, especially the

especially the fluorine because the small ones are going to be they want the

fluorine, because the small ones want the electrons even

electrons even more cuz they're a small

more because they're a small atom.

atom the electrons are going to get closer to nucleus

The electrons are going to get closer to the nucleus.

and the reason why I'm not talking about the the noble gases here is because

And the reason why I'm not talking about the noble gases

these actually these don't form covalent

here is because these don't form covalent bonds.

bonds there they're always happy they

They're always happy.

don't they just you know there are all

They're all these inert gases.

these the inert gases and ER it just means that they don't do anything

Inert just means that they don't do anything.

similar word is inertia inertia means

A similar word is inertia.

you know the tendency to want to stay at

Inertia means the tendency to want to stay at rest, not do

rest not do anything or stay in motion

anything, or stay in motion, but I won't go

but I won't go into that too much but

into that too much.

these are inert they don't do anything

But these are inert.

so these guys react they form covalent

They don't do anything. So these guys react.

bonds up here and when they form

They form covalent bonds up here.

covalent bonds they hog the atoms

And when they form covalent bonds, they hog the atoms.

likewise when these guys down here form

Likewise, when these guys down here form covalent bonds,

covalent bonds they're like you know what you can have the atoms I don't I

they're like, you know what, you can have the atoms. I

don't need them I'm actually happier

don't need them.

without them altogether in fact

I'm actually happier without them altogether.

sometimes these guys actually just give

In fact, sometimes these guys actually just

away the atom they don't even form a

give away the atom.

covalent bond it's called an ionic bond

They don't even form a covalent bond.

we'll talk about that in the next video

It's called an ionic bond.

but you can see the trend is the same as it is for for for ionization energy

We'll talk about that in the next video. But as you can see, the trend is the same as it is for

these guys a lot of energy required to

ionization energy. These guys, a lot of energy required

remove an electron and that's because

to remove an electron.

they love electrons so these guys are

That's because they love electrons.

also very electronegative they're going

So these guys are also very electronegative.

to hog the electrons in in a covalent

They're going to hog the electrons in a covalent bond.

bond these guys very low ionization

These guys, very low ionization energy.

energy very easy to take an electron

Very easy to take an electron away from them.

away from them and that's why they have very low electronegativity they're very

And that's why they have very low electronegativity.

let their that are very unlikely to hog an electron in a bond now the other

They're very unlikely to hog an electron in a bond.

trend that some people sometimes talk

Now the other trend that some people sometimes talk about is

about is the metallic nature of the

the metallic nature of an element.

element metallic nature metallic nature of an element and so you know there's a

lot of things that in my mind kind of

And so, there's a lot of things that, in my mind, I

eyes imagine when someone talks about

imagine when someone talks about metallic nature, I

metallic nature I imagine it should conduct electricity it should be shiny

imagine it should conduct electricity, it should be

it should be malleable and you know I

shiny, it should be malleable.

can kind of bend it without it cracking

I can bend it without it cracking.

that's how I imagine metallic nature but

That's how I imagine metallic nature.

when people talk about in chemistry

But when people talk about it in chemistry, they're really

they're really just talking about a

just talking about a willingness

willingness to give away electrons

to give away electrons.

that's metallic nature and that is you

That's metallic nature.

know that is important if you talk about

And that is important.

something that's going to conduct

If you talk about something that's going to conduct

electricity or be malleable or have kind of the you know have this kind of sea of

electricity or be malleable or have this sea of electrons

electrons available that the atoms can

available that the atoms can sit in.

sit in but the same trend which which

But the same trend.

atoms are very likely to give away

Which atoms are very likely to give away electrons?

electrons well the bottom left right

Well, the bottom left, right?

as you go down the Adam gets bigger so

As you go down, the atom gets bigger, so the electrons are

the electrons are further away from the

further away from the nucleus.

nucleus so the the the nuclear force is or the the Coulomb force is weaker so

So the coulomb force is weaker, so those electrons are

those electrons are more weakly bound

more weakly bound.

and also if you just have one extra

And also, if you just have one extra electron here or two

electron here or two extra electrons

extra electrons there in your outermost shell, you're just

there in your outermost shell you're just like hey let me get rid of them and then I'll have a complete I'll have a

like, hey, let me get rid of them and then I'll have a

complete outer shell so these guys want

complete outer shell.

to give away electrons so they have a

So these guys want to give away electrons.

very high metallic nature these guys

So they have a very high metallic nature.

want to keep electrons so they have a

These guys want to keep electrons.

lot and they want to take more so they

And they want to take more.

have a very low metallic nature in fact

So they have a very low metallic nature.

these are you know these are completely nonmetallic in any way and you know

In fact these are completely non-metallic in any way.

within a and if you were to say within a

And if you were to say, within a group, the trend-- I mean, I

group the trend I mean I did the diagonal but that's in general true is

did the diagonal, but that's in general true-- is that the

that the further you go down a group the rate the size of the atom is increasing

further you go down a group, the size of the atom is

in the outer the outer electrons are

increasing and the outer electrons are

further from the nucleus so the electron

further from the nucleus.

force is going to be weaker or the

So the electron force is going to be weaker-- or the coulomb

Coulomb force is going to be weaker so

force is going to be weaker.

you're more likely to give away electron

So you're more likely to give away electrons.

so you're metallic nature will increase

So your metallic nature will increase as you go down.

as you go down and your metallic nature

And your metallic nature will increase as you go to the

will increase as you go to the left because when you only have a couple of

left, because when you only have a couple of electrons in

electrons in your outermost shell you

your outermost shell, you want to give them away.

want to give them away so metallic nature it goes in the opposite direction

So metallic nature, it goes in the opposite direction.

goes like that but for the same reason

It goes like that.

these guys love to hog electrons these

But for the same reason. These guys love to hog electrons.

lot guys love to give them away

These guys love to give them away.

right so ionization energy increased to the top right electronegativity increase

Right? So ionization energy increased to the top right.

to the top right metallic nature

Electronegativity increased to the top right.

increase to the bottom left the last

Metallic nature increased to the bottom left.

trend we could talk about is just atomic

The last trend we could talk about is just atomic radius.

radius atomic radius and there's a lot

of different ways to actually measure

And there's a lot of different ways to actually measure this.

this and there's no one best way because

And there's no one best way, because obviously, we already

obviously it we already talked about it atom doesn't have a fixed radius so the

talked about it, an atom doesn't have a fixed radius.

electron could show up pretty much

The electron could show up pretty much anywhere.

anywhere so you can just kind of do a

So you could just kind of do a hard boundary.

hard boundary okay 90% chance of finding

OK, 90% chance of finding the electron.

the electron that's your sphere of the

That's your sphere of the atom.

atom or you could say okay if this atom bonds with another atom what is the what

Or you could say, OK, if this atom bonds with another atom,

is half the distance between the two

what is half the distance between the two nucleuses.

nucleus is right if you make a bond like

that then you could call the this is the

If you make a bond like that.

distance between the two nucleuses and

This is the distance between the two nucleuses and then you

then you could say the atomic radius is

can say the atomic radius is that.

and so there's a lot of ways but I think

So there's a lot of ways.

you get the general idea it's just the

But I think you get the general idea.

size of the atom and you could already

It's just the size of the atom.

imagine that as you go down any one

And you could already imagine that as you go down any one

group the size of the atom increases

group, the size of the atom increases.

you're adding on more and more energy

You're adding on more and more energy levels,

levels more and more shells that the

more and more shells.

atom is just getting larger and larger

The atom is just getting larger and larger.

in fact we've used that as an argument as to why as you go down ionization

In fact, we've used that as an argument as to why, as you go down, ionization energy goes down, or

energy goes down or electronegativity

electronegativity goes down.

goes down so the atoms become larger let me make it the atoms become larger as you go down now the one thing that might

So the atoms become larger as you go down.

be a little unintuitive what happens is

Now, the one thing that might be a little un-intuitive is

you go to the right you're adding

what happens as you go to the right?

electrons as you go to the right but

You're adding electrons as you go to the right, but you're

you're also but you're adding them all

adding them all in the same shell, right?

in the same shell right so if this is a nucleus right there and you're in some

So if this is the nucleus, right there, and you're in

shell some orbital shell and obviously

some shell, some orbital shell.

they're not all spheres but let's say in

And obviously, they're not all spheres.

your sub orbital shell you just keep as

But let's say you're in some orbital shell.

you go to the right in a period you just

As you go to the right in a period, you just keep adding

keep adding electrons to that shell all

electrons to that shell.

right this is a super gross

oversimplification and as you go to the

This is a super-gross oversimplification.

right you're also have you have more

And as you go to the right, you have more

protons in the nucleus so this is only

protons in the nucleus.

getting more and more positively charged

So this is only getting more and more positively charged.

so what happens is is that these electrons get pulled inwards they get

So what happens is that these electrons get pulled inwards.

pulled inwards so as you move to the

They get pulled inwards.

right on the periodic table size

So as you move to the right on the periodic table, size decreases.

decreases so size decreases size decreases so the general trend with size

and then you say okay but what about

And then you say, OK, but what about when you

when you go to the next period you're

go to the next period?

adding more you're getting more protons

You're getting more protons there.

there won't that decrease you are but at

Won't that decrease?

the same time you're now adding the

You are. But at the same time, you're now adding the electrons in a

electrons in a new shell that's further

new shell that's further from them.

from them so it gets larger when you get to the new when you go to the new period

So it gets larger when you go to the new period.

so electron size as you go down large

So electron size, as you go down, large.

and as you go to the left you get larger

And as you go to the left, you get larger.

so electron size goes from the bottom right to the top left although in

So electron size goes from the bottom right to the top left.

general the things that are in the in a

Although in general, the things that are in a lower

in a lower period will have a larger size than most things in a higher period

period will have a larger size than most things in a higher

regardless of kind of what group it's in

period, regardless of what group it's in.

but the general trend would then appear within a group the more the higher the

But the general trend within a group, the higher the number,

number the larger

the larger the atom.

the atom within a period that the more

Within a period, the more protons you have,

protons you have the smaller the atom

the smaller the atom.

anyway hope you found those interesting

Anyway, I hope you found those interesting.

in the next few videos we'll start with

In the next few videos we'll start with bonding.

Similar videos:

Valence Electrons
Khan Academy
925.4K views 2.1K likes 114 dislikes 26 Aug 200943% match

Periodic Table Trends: Ionization Energy
Khan Academy
1.1M views 4.5K likes 124 dislikes 26 Aug 200940% match

Molecular and Empirical Formulas
Khan Academy
958.3K views 3K likes 90 dislikes 27 Aug 200938% match

Groups of the Periodic Table
Khan Academy
945.6K views 2.1K likes 123 dislikes 26 Aug 200938% match

States of matter | States of matter and intermolecular forces | Chemistry | Khan Academy
Khan Academy
826.6K views 2.3K likes 171 dislikes 30 Aug 200938% match

Orbitals | Electronic structure of atoms | Chemistry | Khan Academy
Khan Academy
2.3M views 5.4K likes 295 dislikes 25 Aug 200938% match

Van der Waals forces | States of matter and intermolecular forces | Chemistry | Khan Academy
Khan Academy
828K views 3K likes 193 dislikes 01 Sep 200937% match

Ionic, covalent, and metallic bonds | Chemical bonds | Chemistry | Khan Academy
Khan Academy
2.5M views 9.4K likes 395 dislikes 26 Aug 200937% match

Vapor pressure | States of matter and intermolecular forces | Chemistry | Khan Academy
Khan Academy
569.5K views 2.4K likes 109 dislikes 02 Sep 200935% match

Introduction to the atom | Chemistry of life | Biology | Khan Academy
Khan Academy
2.7M views 9K likes 438 dislikes 25 Aug 200934% match

Electronegativity | Atomic structure and properties | AP Chemistry | Khan Academy
Khan Academy
812.7K views 3.3K likes 197 dislikes 13 Jun 201434% match

Electron configurations 2 | Electronic structure of atoms | Chemistry | Khan Academy
Khan Academy
1.1M views 2.1K likes 72 dislikes 25 Aug 200934% match

HD Back Massage Therapy, Relaxing How To Techniques Athena Jezik Austin, Mackenzie ASMR
PsycheTruth
3M views 12.5K likes 1.1K dislikes 29 Nov 201233% match

Diffusion and osmosis | Membranes and transport | Biology | Khan Academy
Khan Academy
2M views 9.1K likes 330 dislikes 08 Feb 201033% match

More on orbitals and electron configuration | Chemistry | Khan Academy
Khan Academy
1.4M views 3.1K likes 136 dislikes 25 Aug 200933% match

Data Types
CS50
61.8K views 185 likes 7 dislikes 07 Oct 201533% match

Renting vs. Buying (detailed analysis) | Housing | Finance & Capital Markets | Khan Academy
Khan Academy
392.6K views 982 likes 54 dislikes 21 May 200833% match

Spectrophotometry introduction | Kinetics | Chemistry | Khan Academy
Khan Academy
587.2K views 2.9K likes 78 dislikes 15 Oct 201033% match

FALLEN GHOSTS DLC REVIEW | Ghost Recon Wildlands
SXVXN
137.8K views 1.3K likes 69 dislikes 04 Jun 201733% match

Boiling point elevation and freezing point depression | Chemistry | Khan Academy
Khan Academy
488.9K views 1.4K likes 117 dislikes 03 Sep 200933% match

Operators
CS50
44.3K views 89 likes 4 dislikes 07 Oct 201532% match

The discount rate | Money, banking and central banks | Finance & Capital Markets | Khan Academy
Khan Academy
175.7K views 368 likes 22 dislikes 11 Feb 200932% match

Elements and atoms | Atoms, compounds, and ions | Chemistry | Khan Academy
Khan Academy
3.7M views 9.6K likes 435 dislikes 31 Jul 201132% match

25 BEST PLACES TO SEE IN PERU 🇵🇪WHERE TO VISIT *HIDDEN GEMS INCLUDED*
Alexander Travelbum II
2.4K views 240 likes 1 dislikes 13 Nov 202032% match

The Best Jeep Wrangler Off Road Lighting | Light Bars + Rock Lights + Flood/Spot Light
ExtremeTerrain Jeep
27.6K views 265 likes 12 dislikes 24 Oct 201732% match

Game Of Thrones Season 5 Episode 10 - Finale TOP 10 WTF and Easter Eggs
Emergency Awesome
1M views 16.3K likes 482 dislikes 14 Jun 201532% match

Important Information about PSYCH-K Balance Processes
PSYCH-K® - Free your Mind
66.8K views 618 likes 14 dislikes 28 Jan 201432% match

DAX functions (DAX3)
Microsoft Power BI
70.2K views 157 likes 7 dislikes 07 Jun 201632% match

TARJETA DE DESCUENTO PARA ÁREAS, CAMPING, TALLERES, REPUESTOS, COMBUSTIBLE, BARCOS...
MEMORIAS DE UNA RUEDA
3.8K views 261 likes 7 dislikes 26 Feb 202131% match

Toro vs Ego - Who Makes a Better Electric Lawn Mower?
Unbox Warehouse
78K views 857 likes 318 dislikes 02 Apr 202031% match

Settings Privacy About Contact Donate