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Do you actually see positive and negative in some particular way, or does it all depend on the particular relationships?  I get confused when numbers appear around a chemical element (I'm easily confused!)

But all the numbers have something in common: I can add and subtract them, so 6 protons + 1 proton = 7 protons (=nitrogen); 6 - 5 = 4 protons (=boron) etc.

I'd like (maybe it's impossible!) to have a similar way to think about positive and negative, some correlation that I can then apply when I stare at something like:

and those plus and minus symbols mean something to me beyond "the lithium ion has one less electron and the fluorine ion has one more electron"

I mean, maybe there's no single model I can hold onto, and I'm wondering if people (such as yer good self) have some model in mind (e.g.--and this is just to show  what I mean by model i.e. a shorthand--"Ah, well, positive is lighter and negative is heavier"

Sommat like that.

And thanks for the support!  

I have often wondered though how it would be to have those associations hard wired elsewhere to then try to absorb the concepts and language of chemistry later in life.

That's where I'm at!

(OT, in your recent diary: have I got it right, that you can hear all those strange youtube videos I post?  So you're in a similar position but swap Chemistry for Music?)

Don't fight forces, use them R. Buckminster Fuller.

by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 09:29:53 AM EST
[ Parent ]
I have tomato and roasted pepper soup. i will answer bit by bit.

First off, when you think negative or positive think negative CHARGE, positive CHARGE. Charge.  Associate the word charge as a concrete property as something quantitative. You can measure charge.

always associate an electron as -
An electron is negative. Think electron think the symbol -  minus. electron. minus. -

REDOX
reduction. electrons are minus.  more electrons, more minus, more negative. think of numbers. say 2. add a minus. 1. add another minus. 0.  You have reduced the number. add a minus, add an electron, reduction.
(gain electrons, reduce the charge = reduction)

oxidation is just the opposite of reduction. Learn reduction and you can work out oxidation. lose an electron, lose a minus therefore gain a plus.

All of this hinges on the movement of electrons. You are following the electrons. Where they go, they take a minus with them, leaving a plus behind them.

Get this out of your head now,

"The positive is comfortable, it has enough, it can afford to lose an electron or two.  The negative is always after a bit more, it wants to grab an extra electron or two (or even three) if it can."

It is the wrong way around. postive attracts negative. positive is missing electrons and needs electrons to balance itself out. negative has extra electrons and will give them away to balance itself out.

The balance of positive charge and negative charge is neutral, no charge.

Assume you started with a neutral. if you have an ion that is positive, +, it is missing an electron, -.
cations, positive, missing electrons. The minus (electron) went somewhere else and left a plus behind.

if you have an ion that is negative, it has extra electrons, -
anions, negative, has extra electrons

I will do another post to answer more questions.

by In Wales (inwales aaat eurotrib.com) on Fri Mar 14th, 2008 at 09:50:11 AM EST
[ Parent ]
This is just exactly the kind of thing I had in mind!  I look forward to your next installment.

(btw, post as much as you like and can--if you are the funky electron provider, then I am WAY positive!)

(: did I get that right?)

(And also: I am going to re-read yours (and anyone else's!) comments late at night (maybe many times!), after having cleared my mind of clutter (in my own way) and with maximum concentration--and slowly! So more please!  And I promise to pay you back with music, only if you'd like, though!)

Don't fight forces, use them R. Buckminster Fuller.

by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 10:08:09 AM EST
[ Parent ]
If I'm providing the electrons, you'll be gaining them... follow the minus.
by In Wales (inwales aaat eurotrib.com) on Fri Mar 14th, 2008 at 10:20:36 AM EST
[ Parent ]
I'm lacking in electrons so I'll be positive for quite a while.

Don't fight forces, use them R. Buckminster Fuller.
by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 07:20:04 PM EST
[ Parent ]
They're just complementary qualities. You could call them red and blue, day, night, zombo and fruvious.

(In fact quarks are divided up into 'colours' which are just another example of complementary qualities, grouped in threes instead of twos, and don't imply actual colour.)

It works like this - things behave in a certain way, and you have to label them with something. So historically scientists pick a word that sort of fits - often not very well, and sometimes out of context - and leave it at that. The people who do the exploring get to choose the words. If their exploring is good, everyone else copies them. If the words are not so good - too bad, everyone is stuck with them.

But you've illustrated a point I've tried to make before about the difference between scientific and creative types.

Creative types view the world through their feelings, and feeling is a moral process. So if they're excited about something - that's good. It's positive! If they're not excited about it - and feeling negative - that's bad.

Scientific types just describe what happens. There's no moral imperative, and while they do excited about things, getting excited - or not - isn't the main point of the exercise. The main point is describing what happens accurately, precisely, and reliably.

So with charge what matters is that opposing charges attract, and identical charges repel. You can put some numbers in and calculate exactly how much this happens.

E.g. to make an old-style cathode ray TV or monitor, you need to flick a beam of electrons around to paint the picture. Because you know the charge, it's easy to calculate how much flicking is needed, and how to build something that does it.

And - this would still be true if you went through the whole of physics and swapped the negative and positive signs around.

The current (sorry...) convention is actually rather stupid, because in a battery electrons flow from the negative terminal to the positive one. So if you think of it in terms of water flowing - which is sometimes useful for electricity - there's a flow from negative to positive.

This makes no sense at all, and it's really just an accident of history that the labelling is as it is.

by ThatBritGuy (thatbritguy (at) googlemail.com) on Fri Mar 14th, 2008 at 10:48:25 AM EST
[ Parent ]
Great comment, thanks!

If the words are not so good - too bad, everyone is stuck with them.

Ah!  You have felt my pain.

this would still be true if you went through the whole of physics and swapped the negative and positive signs around.

I read an example where they used green and red balls--precisely to remove the associations with the words "positive" and "negative", but then the red balls and the green balls did different things (the red balls clumped together and the green balls flew around them, I think), so there was some essential difference between a red ball and a green ball; you could change the colours but that difference was still there.  I'm looking for a model where I can assign some concept to "red ball" (apart from redness) such that the behaviour of the red ball can be (at least partly) anticipated by my associating my model...."Those red balls are like...diamonds, hard to the touch and expensive; those green balls are like....cars; always around and needing roads...."

Creative types view the world through their feelings, and feeling is a moral process. So if they're excited about something - that's good. It's positive! If they're not excited about it - and feeling negative - that's bad.

Scientific types just describe what happens. There's no moral imperative, and while they do excited about things, getting excited - or not - isn't the main point of the exercise. The main point is describing what happens accurately, precisely, and reliably.

Would the two words "qualitative" and "quantitative" apply here?  I mean, I can do both but I need the "qualitative" so that I can keep my "quantitative"...in some human context...I can see a synthesis whereby the scientific description (accurate, precise, reliable) can only be brought into human action (lives....I dunno ....into the realm of human....something) when effective models are in place for us to relate the numbers to something less abstract (as is happening at the moment--for me--with the great discussions here and across the internet about economics); and vice versa those that can simply feel something need to be able to turn these feelings into something quantitative so that one person's experience can be spread out across humans (human society...something like that.)

Don't fight forces, use them R. Buckminster Fuller.

by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 11:26:04 AM EST
[ Parent ]
IEEE - IEEE History Center: FAQS
In the 18th century a number of people made investigations of static electricity. Charles Dufay distinguished between vitreous electricity (the sort created when glass or rock crystal was rubbed) and resinous electricity (the sort created when resin or a wax rod was rubbed). Dufay proposed a two-fluid theory of electricity, the two fluids corresponding to the two types of electricity. Benjamin Franklin proposed a one-fluid theory, hypothesizing that the two apparent types of electricity were, in fact, occurrences of excesses and deficiencies of a single electrical fluid. Franklin introduced the terminology 'positive' and 'negative' to denote, respectively, an excess of electrical fluid and a deficiency of electrical fluid. It was on the basis of certain charging and discharging phenomena that Franklin assigned the designations 'positive' and 'negative', and in the 19th century the terminals of electric batteries were labeled 'plus' and 'minus'. Early in the 20th century it became clear that in most instances of the transfer of electric charge, it is electrons (negative charge carriers) that move, but by then the labeling conventions were firmly established.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Fri Mar 14th, 2008 at 11:46:54 AM EST
[ Parent ]
I think qualitative and quantitative happen later. The key point is really that it's about how you feel, and creative types tend to use their feelings as a guide for making sense of reality.

In my experience creative types approach a problem by asking themselves how they feel and making connections between things, and it's the process of finding things that look like other things and assuming they're connected that keeps them interested.

Scientific types systematise. They like numbers and abstractions, and algorithms to glue them all together.

It's very hard to do both at the same time, and individually both are partial and incomplete.

If you just do the algorithms you can lose the plot and spend time building a system that either doesn't work or doesn't answer the question that really matters to people. If you just do the intuitive feeling stuff you can mistake feeling for understanding - because feeling isn't really a useful model or system, it's a fleeting experience.

What makes science and maths hard is that sooner or later you have to stop relying on trying to experience what you're trying to understand. When the maths gets really hard, you can't do that any more. You start from somewhere familiar, blunder around a maze of twisty little equations bumping into things and feeling blind, and - ideally - fall out the other end into somewhere that makes sense again.

I've always had problems at that point. I suffered through maths A Level making very little sense of mechanics because the teacher hadn't bothered to make a simple connection to things I'd learned earlier. Once I got that, it became easier.

The more advanced the science, the harder it is to be physically intuitive about it. Some rare people seem to have a kind of mathematical intution which is a substitute, kinda sorta.

But I don't, and a lot of professional scientists don't seem to either.

And therefore - hard. Sometimes hard maths is abstracted to make it simpler and more intuitive to work with again.

But you can still end up with:

Which is not necessarily intuitive to most people. ;)

by ThatBritGuy (thatbritguy (at) googlemail.com) on Fri Mar 14th, 2008 at 12:16:08 PM EST
[ Parent ]
but then the red balls and the green balls did different things (the red balls clumped together and the green balls flew around them, I think), so there was some essential difference between a red ball and a green ball; you could change the colours but that difference was still there.

That, at least partly, is because the model you're using is so simplified.  It can't hope to explain why the protons stick together, because they shouldn't.  They're all positively charged and so should repel each other and fly apart.

(Don't worry yet about why they stick together.  Just accept that it gets more complicated later on.)

The terms positive and negative were applied consistently to charge before the discovery of the electron.  Unfortunately this turned out to be the wrong way round for easy visualisation.

A rather value-loaded metaphor I think I've just made up is that when you're positive, you attract what you need, and when you're negative, you lose.

But, really, I visualise electrons a bit like little packets of negative charge.  And because I know electricity is a flow of electrons, it's therefore logical that it flows from maximum to minimum, ie the negative to the positive electrode.

If an ion is negative, it's because it's got an extra packet of negative charge...

And...read this slowly...you already know that two minuses make a plus.  Minus "minus one" is one...if an ion is lacking an electron, it will be minus one unit of negative charge.  Therefore it will be positive.

I hope this makes sense...  :)

by Sassafras on Sat Mar 22nd, 2008 at 05:03:12 PM EST
[ Parent ]
It can't hope to explain why the protons stick together, because they shouldn't.  They're all positively charged and so should repel each other and fly apart.

They don't. Two protons can never form a nucleus. That's what you have neutrons for (or rather, that's what neutrons do, if we want to avoid the pitfall of anthropocentrism). If you want a toy model that'll serve you well enough and remain useful pretty far into your studies (if not forever, depending on your line of enquiry), you can think about neutrons as a kind of glue that holds the positively charged protons together.

And by the time that model is no longer adequate, protons, neutrons and electrons should be such familiar mental constructs that they have long transcended the initial toy model.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Mar 24th, 2008 at 11:15:45 AM EST
[ Parent ]
always associate an electron as -
An electron is negative. Think electron think the symbol -  minus. electron. minus. -

Ah!  I hope I get this right:

where I see a - sign, it means "electrons".  If I see a + sign and a - sign, I can imagine a line running from the plus to the minus: the electrons are over at the - end because - means 'electron(s)'.

A + atom has less electrons than when it was neutral--it's proton to electron balance is skewed.  There are more protons than electrons (in a single atom)

A - atom has extra electrons.  There are more electrons than protons.

In a pair, with either ionic or covalent bonding, + and - tell me which atom in the pair has the most electrons  above its natural (pure element) count.

So I need to have the electron counts memorised for each atom--the valence electrons--or the bonding electrons...

But...the + and the - are the answer: the atom with the minus has more electrons than normal when compared to the atom with the plus.  (Or: the atom with the plus has less electrons than normal when compared to the atom with the minus)

Don't fight forces, use them R. Buckminster Fuller.

by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 07:18:41 PM EST
[ Parent ]
In here, you are jumping ahead of yourself and getting muddled.

a few steps you need to go through include learning about electron levels/shells and the number of electrons in each level.  Look at the periodic table and the number of electrons in the outer shell - which is the key thing that determines it's chemical properties.

Let's take lithium and fluorine since you put them in above.

The lithium atom has 3 electrons. 2 fill the core shell (first level has a maximum of 2 electrons).  This means there is one electron in it's outer shell.  To get the full compliment of electrons in the outer shell it would need to pick up 7 electrons which in energy terms would be HUGE and so completely not happening.  So the easiest thing for it to do is lose that spare electron to another atom that wants to fill it's own shell.

Lithium can completely give it's electron away to say fluorine which needs one electron to fill it's outer shell with. Because Li completely transfers it's electron over to F - they become ions. Li+ and F-
The anion (F-) is attracted to the cation (Li+) and so they hang about together through ionic bonding.  But F- now 'owns' that electron.

Now atomic mass is not always directly equated to the number of electrons because you can have isotopes which have extra neutrons, the particles with no charge.  But protons and electrons will be the same number of each in an atom.

Elsewhere in the periodic table we have atoms that need a number of electrons but instead of completely giving or taking electrons, they share them. Covalent bonding.

Some atoms have a greater affinity for electrons.  oxygen is one of those. but tricky because it has lone pairs and can form multiple bonds which i will only confuse you with at this point.

So let's take your methane molecule in the main post.
Carbon has it's snug pair of electrons in the core shell. They are happy. But, carbon needs 4 electrons for it's outer shell to gain the full compliment and thus be energetically stable.  It is not energetically favourable to give away or receive 4 electrons in the sense that Li can give away one and F can gain one.

So Carbon shares.  Each H atom only has one electron and needs 2 to fill it's shell and be energetically stable.  

So an H shares it's one electron and C shares one of it's electrons to pair up. So they cheat a little bit in filling their shells.  

4 H atoms share with one C atom so that C 'borrows' 4 to fill it's outer shell and each H 'borrows' one to fill it's outer shell.  In reality, these electrons whizz around all over the place, so the H electron can be found anywhere over the molecule, not just around the H atom, the all mix in together to form an electron cloud that holds the molecule together. But that is another model.

Will it help if I tell you the kind of music I like so that you can dig out other stuff for me to try listening to?

by In Wales (inwales aaat eurotrib.com) on Fri Mar 14th, 2008 at 10:18:25 AM EST
[ Parent ]
I'm about at the stage where I know that the 4s orbital fills prior to the 3d orbitals, and I am about at the point where I can make sense of larger molecule diagrams (not quite there, but closer than I was.)  (And all those transition elements filling in the d orbitals...that's my next area of focus)

(I have a feeling I'll be asking for one of those 3D molecule kits for my next birthday (or maybe buy myself one prior) as three dimensionality is one of the keys (for me, in understanding--that these molecules have height, depth, and breadth--that the extend outwards in various directions based on the electrical charges--120 degrees, tetrahedrons--hey, I had to sit down and ponder the beastie with four sides, all of which were triangles)...

So I've moved ahead, but I realised that this issue of plus and minus was getting in the way.  From your other post I'm thinking that I can relate it to a number line

(You know all this of course, but I like the way you can catch my mistakes so...)

,

I can imagine (this could be my model) that positive and negative are at opposite ends such that electrons are at the negative (-) end, and the protons are at the positive (+) end, and they're...tugging towards each other (trying to reach their beloved zero point of no charge and so no more crazy attractions) such that 'negative' means: 'towards the electron end' and 'positive' means 'towards the proton end' and so a gain in electrons means a movement towards the electron (-) end, while a loss of electrons means a movement towards the proton (+) end, and thusly positive and negative and gain and loss come together again--at least in my head!

Does that sound about right?

Will it help if I tell you the kind of music I like

Just a few disjointed adjectives are fine--ya know...just some flavours, no need to use too many words (ah, the joys of music!  Oh, no naming names!  You might love a band and I hold some bizarre prejudice against them because my best friend's sister once went out with the bass player and it all finished badly...etc.)  My experience is that most musical fields will have something comparable so I can go and hunt up some examples and see how they match.

Don't fight forces, use them R. Buckminster Fuller.

by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 10:45:13 AM EST
[ Parent ]
so a gain in electrons means a movement towards the electron (-) end, while a loss of electrons means a movement towards the proton (+) end

Yeah that works.

And you may still be jumping ahead with the s,p,d,f orbital stuff unless you have grasped ionic and covalent bonding through use of the Bohr model (circles of shells around the atoms).  But the cool thing about the s,p... orbitals is that they have shapes and this then leads to understanding the shapes of molecules and it is where lone pairs come in too.

Oooh.

You can use plasticine and chopped up straws until you get a modelling kit.

I don't think I know how to describe music in adjectives yet.  Sometimes ambient stuff for chilling out to when the mood suits, I like the way the music can focus me or just be a background.

And other times I like the energy that music gives me.  Sometimes I like stuff to get my teeth into. Not massively into classical by itself. Too much very high pitch hurts. bass that makes my heart beat to follow is good. or when music seems to have some humour to it. Now I am going.

by In Wales (inwales aaat eurotrib.com) on Fri Mar 14th, 2008 at 11:06:53 AM EST
[ Parent ]
I'll post something next week for ya!

Don't fight forces, use them R. Buckminster Fuller.
by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 11:13:31 AM EST
[ Parent ]
That's almost it.

The easiest way to understand this is to get some magnets. It's actually the same force (more or less, ignoring complications about something called spin), but you can pick up a magnet and play with it, which is hard to with an electron.

More electrons -> bigger magnet-type effect.

North/South are another historical accident. +/- and N/S are more or less interchangeable in this context. So if it helps you can think of electrons as being the North half of a magnet and protons as being the South half. (Or vice versa - as long as they're complementary.)

That's not the 'proper' explanation, but it's not a bad guide to how they act.

The only other complication is that when you build your 3D models, keep in mind that everything is moving. The connections are more like springs than rigid links, and you can make them twang in different ways, or spin the model as a whole, or make and break links between molecules, and all of these will be happening all of the time, in differing amounts.

In a solid the links will be stiff, although they'll still be vibrating slightly. In a liquid they'll be forming and breaking continuously, which is what makes liquids flow. In a gas - pffft - not much linking happening at all.

This also applies to the connections between the protons and neutrons in the nucleus. You can make the nucleus ring like a bell by kicking it with a vibrating magnetic field. It will 'sing' at some frequencies, and this creates a signature 'sound' you can use to identify it.

by ThatBritGuy (thatbritguy (at) googlemail.com) on Fri Mar 14th, 2008 at 11:25:03 AM EST
[ Parent ]
I'll repeat to you what I wrote to In Wales:

I am going to re-read yours (and anyone else's!) comments late at night (maybe many times!), after having cleared my mind of clutter (in my own way) and with maximum concentration--and slowly! So more please!  And I promise to pay you back with...

A lovely cup of tea, minimum!

Really really very much appreciated, thanks!

Don't fight forces, use them R. Buckminster Fuller.

by rg (leopold dot lepster at google mail dot com) on Fri Mar 14th, 2008 at 11:29:17 AM EST
[ Parent ]
But one thing to remember when playing with magnets is that with protons and electrons, it's possible to have only a + or only a -. That doesn't happen with magnets: They always have both a North and a South pole. That means that while everything you can do with (static) magnets can in principle be duplicated with (static) electrons and protons, electrons and protons can do a lot of interesting things that magnets can't.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Mar 24th, 2008 at 11:33:19 AM EST
[ Parent ]

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