Question: If opposites attract, why and how do atoms of one kind stick together

[BurtWorm]

I ask this question because it came out of a discussion I was having with my daughter about elemental chemistry. She wanted to know if there was such a thing as a gold molecule. I was about to say yes, but then I realized that in molecules, atoms share electrons (don't they?). That doesn't happen when you have pure gold, though, does it? Do gold atoms share electrons with each other? Is that how they wind up forming the solid substance we call gold?

I feel dumb asking, but it's been a while since chemistry class, which I sucked at anyway.

[meegbear]

1. The Google is your freind ...

http://www.google.com/search?hl=en&safe=off&q=atoms+stick+together&btnG=Search

[BurtWorm]

4. In other words, you don't know either.

;)

[MineralMan]

6. Neither did I, but I clicked on one of those links at the

Google search, and now I do. That's the thing about questions like yours...the answer's already written down somewhere. It takes a lot of time to spell it out here. That's why folks suggest Google, I think.

[Cleita]

2. Are you saying that there are gay atoms? n/t

[Xipe Totec]

3. Valency: sticking atoms together

http://chemistintheory.blogspot.com/2008/02/valency-sticking-atoms-together.html

[BurtWorm]

7. That was helpful.

Thanks!

:toast:

[muriel_volestrangler]

9. However, that doesn't explain how pure gold behaves

Pure metals (as opposed to compounds of metal - eg sodium chloride, or the lithium compound in that page, which is ionic bonding) have 'metallic bonding' (heh, that surprised you, didn't it?)

A simple explanation:

Force of attraction operating in a metal that holds the atoms together in a metallic structure. In metallic bonding, metal atoms form a close-packed, regular arrangement. The atoms lose their outer-shell electrons to become positive ions. The outer electrons become a ‘sea’ of mobile electrons surrounding a lattice of positive ions. The lattice is held together by the strong attractive forces between the mobile electrons and the positive ions.

The properties of metals can be explained in terms of metallic bonding. Metals conduct electricity as the electrons are free to move. Conduction of heat occurs by vibration of the positive ions as well as via the mobile electrons. Metals are both ductile and malleable because the bonding is not broken when metals are deformed; instead, the metal ions slide over each other to new lattice positions.

http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0030538.html

A more complicated one, involving quantum mechanics (and I've no idea how accurate it is): http://en.wikipedia.org/wiki/Metallic_bonding

[RandomThoughts]

5. Chemistry, with a thought.

Some atoms can form molecules with only that one atom as a component, the shells of electrons are filled in with electrons from a like atom.

Look at the periodical table, you will notice that carbon has 4 extra electrons in outer shell, and is missing 4, so it can bond with other carbon atoms.


I would guess gold atoms have an incomplete outer shell, that gets filled in with electrons from other gold atoms. Although gold likes to bond with other elements also, so thats why it gets processed to remove the impurities. In nature I would surmise most of the time gold starts with many other atoms, making combinations of metals in the nuggets.

On a more philosophical point, gold often represents righousness, and there is a phrase about refining gold in the fire. Or removing the impurities. This can be seen as how a man removes the parts of himself that are impure over time, sometimes with the aid of the strife of the fire.

Some people take this concept to groups, and believe they are gold, and others are other things, and must be seperated from their group. The problem with this is they have to claim they are gold, and others are not. They make a judgement of self rightousness, before working on their own purity, or rightousness. And they also do not recognize the gold in others.

We all do this sometimes, that is why I think alot of groups speak of working on the piece of lumber in ones own eye, before working on the speak in your neighbors.

[On the Road]

8. Atoms are Generally Not Opposites

Unless they're positive or negative ions, they have zero charge. They stick to each other through one of three kinds of bonds:

Ionic: They trade electrons back and forth (metal to nonmetal)
Covalent: They share electrons (generally nonmetal)
Metallic: Electrons are shared among multiple ions (metal to metal)

Within an atom, however, opposites do attract. Specifically, the electrmagnetic force causes protons in a nucleus to repel each other. The nucleus sticks together because there is an another force, the strong force, which at very short distances is more powerful than the electromagnetic force.

Searching specifically on some of those terms should make it easy to go to whatever depth of understanding you'd like.

[HiFructosePronSyrup]

10. By bonds, of course.

There are many kinds of bonds.

There are ionic bonds. Probably the simplest to understand. Where you have a positively charged atom next to a negatively charged atom. I should be saying "ion" instead of atom, but I think we all get it. It's not necessarily just two charged atoms. In, say, a crystal of salt, you've got lots of positively charged sodium atoms and negatively charged atoms all arrayed in a big network. So you can have two sodium ions near each other if you've also got chlorine ions nearby.



There's covalent bonding. Electrons like to pair up into orbitals, with one electron spin up, and the other spin down. So if you've got an atom with an electron sitting all lonesome by itself in an orbital, it can hook up with the electron from another atom to form a molecular orbital. Like hydrogen, for instance.) Halogen atoms stick together the same way. So does oxygen. Sulfur. Nitrogen. Carbon. And others.



There's metallic bonding, which is what gold does. In metals, the electrons are very loose, so they just sort of float around with the positive metal nuclei in place. Gold doesn't form molecules, since you need ordered, repeated structure to have a molecule. But you can have things called gold "clusters." Which are just several gold atoms sticking together in tiny little chunks. That's probably how most elements stay together.



There are numerous intramolecular forces.

Atoms have a property called electronegativity. That's how closely they pull on electrons. Metals, as you might deduce, have poor electronegativity. Metals like sodium have very, very poort electronegativity, part of the reason why it so commonly has a positive charge. If you've got two atoms with different electronegativity, you can induce a partial charge. One atom will have a partial negative charge, the other has a partial positive charge. And you can get molecules to stick to each other quite strongly with these partial positive charges. It's confusingly called "hydrogen bonding" and it gives water its strong surface tension, for example.



(in that image, the little greek letter delta stands for partial charge)

There are van der waals forces. Electrons can move around atoms and molecules. So while electrons are on one side of a molecule, there's a partial positive charge on the other. This can cause atoms of one type to stick to atoms of the same type on another molecule. All the little hydrogen atoms in fat molecules stick to each other this way, giving butter some solidity.

If an atom can't let go of any electrons (it has high electronegativity) and all its electrons are paired up, it won't stick to other atoms. Nobel gases are like this, and that's why they're gasses.

[Orrex]

11. Good advice

In these troubled economic times, it's probably a very good idea to by bonds.

[laconicsax]

12. God holds them together with the force of His will.

:hide:

[moggie]

13. Jebons

[Nihil]

14. *snort*

:spray:
:spank:

[anigbrowl]

15. Deleted, as #9 is by far the clearest explanation