Lec 3 | MIT 5.111 Principles of Chemical Science, Fall 2005

[kizinfino]

please..could somebody recommend me a book about this/these subjects?. Thank you.

[Morophin3]

That would be great if someone edited in the pictures from the slideshow she is showing the class.

[RowenaRebecajw141]

hehe keiner deutsch hihi

[WitantoCom]

liked this

[SabretoothSnowMan]

This is going to have be troubleshooted.

[SabretoothSnowMan]

This is an error because Univeristy material is immune to copywirte law.

[amrosik]

I WANT TO SEE THOSE SLIDES!!!!!!!!! MAN!! why did you even upload this lecture serie? i cant get anything out of it

[GrBla123]

how can I see the experiment.Due to  protection rights we can not see what is going on . So what is the point of broadcasting half of the class. I want you to look at this green wave and that blue wave. I can not see the waives. I wish google did not buy youtube

[ASeventhSign]

I got it bad, got it bad, got it bad...

[cards0001]

wow impressive well explained !!

[recyclingismylife]

the graph describes the electric field in terms of time, but she doesn't say what changes the electric field IN time to make it oscillate from positive to negative potential. Does anyone know what may cause that to happen?

[irenakolek]

pity there is no slides she uses. but i acctualy enjoy her lectures, comparing with other 5.111 with catherine.. i think sylvia just speaks more clear and i get her way of explaining easier to understand ..

[giovanni9107]

@happyman

The thing is that according to what scientists knew from electromagnetic phenomena, electrons(like all charged particles) should transmit energy in the form of electromagnetic waves when their velocity vector changes. In the case that the energy they lose is kinetic energy, then they would of course slow down and eventually crash against the nucleus, if it's electric potential energy then the same thing happens. That is what physicians could not explain at that time. Hope it helps.

[redsolarearth1]

Happyman, I believe you may find your answer at the wikipedia article... Atomic_orbital electrons dont really like being at the nucleus.

[freezazoid]

wow.... her weird accent is so distracting that I can't even pay attention to this. Her "a's" are particularlyt bad. Is this like a minnesota accent I assume?

[clapascual]

cannot the slides

[recyclingismylife]

She (the prof) says at 10:30 or so that the magnitude of the electric field reaches a maximum potential and then changes direction. I have two questions: What changes the magnitude of the electric field, in other words, what increases the potential difference between the two polarities; and also, what causes the direction to of the electric field to change once the maximum potential has been reached? Anyone know?

[iamsnail]

@jaguarclaw

Atom is chemical particle. Chemical particles are those particles that have electrons whit them. Atoms are made from smaller particles called quarks. And molecyles are made from atoms.

[mike29571]

An electric field is simply a moving magnetic field. E Field = kg m / q s^2. M Field = kg / q s. A photon is the transmission of magnetic flux. Moment of Inertia / q s.

[happyman]

but the earth keeps going around the sun without collapsing into the sun?? that didn't take quantum mechanics to explain? why can't electron be explained this way?

[jordan1mariano]

Man, i'm happy with that question. Look, quantum mechanics tells about what happens in the lengh of a atom, or should i say: it describes what happens in atomic's magnitude. In other hand you have the classical mechanics (newtonian mechanics- as you wish) that describes what happens, in our size of peceptable things, in terms of speed, trajectory and etc. so as you will never mix watter and oil you will never mix these teories.

[bloomingdedalus]

Because Centrifugal force holds the Earth in place. Electrons don't orbit like the earth orbits the sun.

[paisiello2]

One problem is that, since all charged particles emit electromagnetic radiation when they accelerate (change speed or direction), an electron would lose kinetic energy (by emitting radiation) as it "accelerated" around the nucleus - caosing it to sprial into the nucleus.

[redsolarearth1]

@paisiello2 the electrons are not accelerating around the nucleus, unless they absorb energy

[redsolarearth1]

@happyman because an electron is not a planet and the nucleus is not a star

[happyman]

@redsolarearth1 and in what way exactly?

[redsolarearth1]

@happyman

a star is a ball of nuclear reactions, and superheated gas (plasma), and the nucleus of an atom is made of a few protons and neutrons, and these arent really doing anything, and certainly arent at temperatures in excess of thousands of degrees. An electron is a nebulous cloud that occupies a large vaguely defined shape around the nucleus, it is not spinning around the nucleus. The size of atoms is so small that gravitational force is negligible.

[happyman]

@redsolarearth1 it is not obvious to me how quantum mechanics was "invented" to explain the fact that electrons are not falling into the proton... or at least it is not obvious in the narrative considering that planets didn't require quantum mechanics to explain why planets don't fall into the sun.

[giovanni9107]

@happyman

I really hate trolls but this is inevitably going to sound trollish: she messed up in the last video. If electrons are rotating around the nucleus then the fact that they don't crash against the sun taking only in account the Coulomb's force can be explained with classical mechanics You are completely right.

[HotRock2010]

@happyman electrons are at lot less massive and move at nearly the speed of light.

[Obito313]

@happyman gravity doesn't take electric charge. I think?

[MassimoPiai]

@happyman because electron is a CHARGED particle, so it must radiate energy if accelerated.

[Guppypants]

I like this. This lecture costs a fortune to see live.

[tamerseeker]

@Guppypants false, no it doesn't. you can just walk right in. proof of which is the guy in the mit hat, he's me.

[DARTMOUTHNERD]

kool letures im pre-med and taking chem next term

[namaoui]

the guy shooting must have a big electrical crash on the teacher

[edayxe]

Too bad the person shooting this video did not zoom in to where the teacher is pointing.

When the teacher is using the computer to show a slide or a graph on the screen, the video person shoots at the teacher instead of zooming into the screen. So the class can see the screen but the Youtube audience can only look at the teacher. Too bad.

[CoreCorrupter]

The slides are often taken from the text which is not licensed the same way as the lectures.

[asupara4418]

I am first time to hear the question from th e audiense.

[F00dTube]

You mean: "This is the first time I'm hearing a question from the audience." or "This is the first time I've heard a question from the audience."

[asupara4418]

Sorry, I wanted to say "This is the first time I've heard a question from the audience."

During this movie when I'm watching, almost all students or audience did not have any questions except one.

[wexarexthexStorm]

Second! I didn't have to do that.

[isobelpoe]

First! (Just had to do that!!)