Soapbox

Look im really stuck, and as quite a lot of you out there have done A-level chemistry, I wondered if somebody could explain polarity in covalent bonds to me. Please.

TomT

I did Chemistry at a level and came to this conclusion,

Economics looks easier.

So I swapped, I suggest you do the same.

Well, if you have a covalent bond between H and O, for example, they are sharing electrons in the bond (definition of covalent bond). However, each element is slightly polarised.

The Oxygen atom is slightly negative and the Hydrogen atom is slightly positive. This is to do with stability of the electrons in their subshells. Oxygens like to shed electrons, hydrogens like to eat them.

This particular O-H bond polarity forms the basis of why things disolve, or don't, in water.

How much of this do you need to know Tom? Maybe I should email you?

Sorry, that's not even true what I said. I got confused. Oxygens do not like to shed electrons. They need an extra two for a full house. I would have changed it, but I can no longer edit threads. :-( I feel powerless.

Anyway, I do know what I'm talking about as I took it last year and paid the examiners to give me a brand new spangly A, so the offer still stands.

Yes pleasy, how you work it out, which is elecotronegativley stronger, im working from the salters advanced chemistry book if that helps.

Cheers

TomT

That Sal...she's all quiet for ages and the she comes back with covalent bonds!

Kinky I call it, just plain kinky!

Yep thats the one, wait till she explains ionic bonds, and shared electons, and nucleus pulling power.

Tom whooooooo covalent bond T

And this is Chemistry you say...Hmmmm I'm thinking I may take a GCSE nest year...Is totty guarenteed?

Tom just wait till you get to the fun of thermodynamics in chemistry then you'll be enjoying entropies enthalpies and Gibs free energy, but I won't tell you any more other wise you might not like it before you even get there!
On the subject of electronegativity the electronegativity of an element decreases down the group wiht flourine being the most electronegative element
This may or may not help U
But good luck and if you get more than an N then you're a better chemist than me :-)

I have a test next wednesday arrrrrrrgh and Sally hasnt emailed me, but i know a lad who is super clever and even talks to Steven Hawkins, the only problem his hes a bit to clever. Sally I dont suppose you can fit in all the stuff about plancks constant and avargados constant can you.

Tom mate I'd email you my notes but I think you'd be better sticking with Sal as She got an "A" as opposed to an "N"!

I'm lovin A level chemistry at the mo, we made aspirin today. I've still got a Q for AS but i dont think they want to give me a real letter.

Anyway yeah for the examy thing just remember to learn approximate values for van der Waals, hydrogen, and covelant bonding. As for electronegativity, remember the mnemonic Noddy Go Away so that you'll know that Nitrogen is more electronegative then Fluorine which is more electronegative than Oxygen. (note that Noddy Go Away is the clean version).

Meanwhile would somebody please explain connected rates of change,- differentiation, P3, A level maths? I haven't a clue to be honest.

Can't help on that one ask me any chemistry thing and I cna probably sort it as my course has a lot of chemistry in it.
On the subject of A level, I did enjoy my chemistry but I just didn't like one of my teachers attitude towards me, but never mind now I'm at uni and am looking at going to norway for a year on an industrial placement!

Erm ok then, is a spillage of ethanoic anhydride on a book in my lesson on wednesday likely to have effects in my lesson tomorrow?

Never mind all of that hokum stuff and bluff! I just wanna know why it is there's that odd white-blue flash of light visible when opening self seal envelopes, by depeeling the glued section in the morning post, please?You can notice this odd effect quite clearly when opening such mail in the described way in any even slightly darkened room or corridor.

Also, another odd thing! Why is sweat yellow? You see this when cleaning yourself in camp with white coloured wet wipes type stuff, as they go bright yellow! Is that the urea being sweated out through the skin that provides that colour, do you think? Anyone know?

Well, why yes!

Old threads can be fun sometimes, I think!