Atomic bonding question

OK guys, I need help and loads of it! Snow days aren't good when you don't understand something.

Covalent Bonding (or just bonding, I've been told ionic is still classed as bonding for teaching senior school but it isn't really, not in my eyes).

How do the elecrons pair up?

Are they limited to just the space in which the orbitals overlap so both atoms feel complete?
Do they have to be of the same spin to pair up (I think so but aren't sure)?
Do orbitals have to bend to form pi bonds or do the electrons leave the p shell?
And does the sigma p orbital bonding mean both little arms of the p shell have to bend over to match up? Does that make sense? Not really.

And here's an unrelated one. I comprehend how spin keeps electrons in the same shell from hitting each other, but how do s electrons not hit the electrons in the p orbitals? Because the s shell overlaps all the p shells and d shells and whatnot so how do the electrons not bump into each other. OK they repel each other but does that alter the "shape" of the shell, are electrons less likely to be found at certain points, especially in the s orbital, if there is a chance they could collide? Or is this a really, really stupid question?

And if anyone wants to pass this onto a chemist please feel free. I just don't get this and the lecturer doesn't understand my questions! (Then again, I'm not convinced I do some of the time either.)

pmsl.

sorry Ryn, I know it isnt funny that you dont understand something, but I have NO IDEA what language you just spoke! lol
So I am sorry I cannot help you but I am subbing this anyway cos now I really want to know if those little arms are going to bend or not!! :)

LOL. I don't have to understand it, which is why the notes and books don't go into enough detail, I just want to! Isn't that what a University education is supposed to be about?

Ryn, I'm currently sitting here tearing up my chemistry degree. I feel like I *should* be able to answer your questions, but I just can't!

The one thing I can comment on - I was initially under the impression that electron orbitals were a "path" that the electrons ran around on. They aren't. They actually kind of buzz around in a "cloud" that's that rough shape. They can even be outside of that orbital shape - there's just a higher probability that they are there.

The bonding questions are hurting my head - if something pops into my brain later on, I'll come back.

Of course, it's over 10 years now (:o!!!) since I finished uni, so it's entirely possible that everything I learned is now seriously outdated!

BW

Can you google the answer or look up bonding in wiki?

Sorry i have no idea.

*Struggling to remember what I was taught in chemistry at uni* .... I think BW has it fairly right though, they aren't confined to a particular orbital, there is just a higher probability that they will be found in a certain orbital, so the electron cloud is really just a fuzz surrounding the nucleus. Sorry I can't answer your other questions...it's way too early in the morning for chemistry, that and the fact I left uni over 2 years ago! Lol

I understand (for the most part) the cloud theory, and even that if you DO draw the orbital as a line it has to be two wavy lines for two electrons with different spin... I can just about visualise how the electrons don't hit each other or cross orbitals up to neon (10), but then it's just too hard to picture all the different electrons whizzing and spinning and not hitting each other. Bonded electrons may be easier to picture as a cloud anyway, especially if they're trapped in the bonding area.

I mean, the P orbitals loop out and cross all the S orbitals (although the electron is more likely to be found between S-shells), but then the D(x squared) orbital... now the little doughnut shaped orbital, how does that not collide with, say, the 2pz and 2px electrons? Or does it distort the 2p electrons so they're more likely to be found further out, which will then surely affect the 2s shell...

You know, I think this is too hard. I need to know A-level chemistry, which is just "there are different orbitals which explains electron pairing for bonding, they are s and p." I really don't have to fret too much more.

And the idea of shell distortion for bonding is interesting, because that would change ALL the electrons, wouldn't it?

I just get concerned that everything will explode now I see how precarious it must be LOL.

:) feel free to bring on genetics or cytology questions and see how my brain fails me!

same situ as BW - i have a chemistry degree but grad over 10 years ago and not used it since so what should be very simple to answer - i am clueless!.....then again i am clueless to most things these days!
good luck to finding your answer - i would look in my books but they are at dh's parents in Norfolk in the UK!

Julie x

See if this helps at all!

It's difficlut to answer the question because of the question itself. Orbitals and electron spin etc are part of quantum mechanics, and quantum mechanics is a mathematical model and really can’t be translated into a simple, what I call, ball and sticks, model very easily. For example we talk about electron spin, but electrons aren’t spinning like little balls because they have no size! Also it is impossible to locate the position of an electron, so bumping into each other is not a concept.

Orbitals are regions of space where there is a high probabability of the electron being located and those funny dumbbell shapes etc are just that, regions of mathematical probability, the denser the orbital the more probable the electron is located there. When orbitals overlap that just gives a region where there is greater probability that the electron is there. The closest we could say to a simple ball model is the electrons spend more time there. That’s what causes two atoms to bond together, like two hydrogen atoms. The two 1s orbitals overlap so the two electrons spend more time between the atoms and therefore making a negative region between will hold (or bond) the two positive proton nuclei together.

And ionic bonding is a type of bonding because atoms, whose electrons have been transferred to other atoms, are attracted to each other, or bonded. There are other types of bonds. Bonds are just attractions. Molecules are bonded to each other. That explains why water is liquid and not a gas. Metal atoms are bonded to each other, so most metals are solids at room temperature.

So the real answer is, it is very difficult to picture atoms in a mathematical, quantum mechanical, model.

Not written by me I must add!

Thanks, Lee, that was really - and I mean really helpful. It put into perspective all the knowledge in different parts of my brain, coalated it and then turned it into something useful! Visualising this in four dimentions helped a lot too, that is what was missing for quite a while.

OK, so let's see if I've gotten this right:
Electrons are weird. They're not particles, they're not waves, they're both, depending on what you want, and neither, so you can't pin them down - the little tricksy buggers.
Sigma bonding is when two electrons with the same spin overlap in two different atoms. They are then "trapped" in the bonding area.
Pi bonding is when two electrons with the same spin are not overlapping but parallel; the arms of the p shell stay upright but also stretch out to meet each other and the electrons are found in this stretchy bit. (Pi bonding explains why double bonds are so rigid and can't rotate.)

If I have this right, can anyone help with this question please?
Four bonds. Tetrahedral shape.
How do you distort the shells so much to get that? You have a sphere and thee other orbitals at 90 degrees to each other! How does it all twist into the tetrahedral shape? (I just realised how weird this shape is tonight in relation to the shapes of orbitals so there may be a simple answer just I can't see/find it.)

Cheers!

I'll send you a pm in a sec :)

ETA..eeek! I forgot!..Promise I'll do it now!