How does the electromagnetic force bond atoms together?

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In summary, the conversation discusses the concept of touching and chemical bonds. It is argued that when sitting on a chair, there is no actual physical contact between body parts and the chair, but rather interactions at a molecular level. It is also pointed out that metal bonds do not hold together the entire body, but rather a layer of oxide forms to protect it. The definition of touching is debated and it is suggested that most atoms in the body are indeed chemically bonded. The conversation also touches upon the complexity of the human body and the lack of simple answers.
  • #1
exfret
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I thought this when I was pondering how, when you sit on a chair, you're butt isn't really touching the chair; it's just interacting at short distances with its electrons. After thinking about that, I realized that your torso isn't touching your butt either, it's just interacting at short distances with its electrons as well. So, if your torso and your butt are pretty much as connected to each other as your butt and the chair, then why is it that when you stand up from sitting in the chair, your butt comes with you, but the chair doesn't? I understand that metallic bonds hold together metals sometimes, but those can't possible hold together your whole body, right, or can metallic bonds operate on large chunks of nonmetals and what-not mixed together as well? Also, if something like metallic bonds do hold together your body, then why wouldn't they attach you to the chair once you sat on it?
 
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  • #3
If my torso was touching my butt, I would be shaped like a pretzel. What is this fixation you have with things touching your butt?
 
  • #4
Drakkith said:
Here are the different types of bonds and a little of how they work: http://en.wikipedia.org/wiki/Chemical_bond

I was kind of hoping that someone wouldn't just give me a link to a huge page on Wikipedia and say, "Here, the answer to your question is probably somewhere inside." I'm not lazy, but I'm not going to waste my time reading over a whole Wikipedia page that may not even contain the answer to my question. If I wanted a Wikipedia page, I would have brought one up myself. Is there a specific part of that page that you think will answer my question? If you find a web page that you think is interesting and that relates to my question, then I would gladly read it as long as you include a reference to the exact part of the page that relates to my question. Do you have something useful to share, like any knowledge about the different types of bonds and/or how they might relate to sitting in a chair? If you do, then it would be great if you could share that knowledge with me, because I am very curious about this chair thing.

SteamKing said:
If my torso was touching my butt, I would be shaped like a pretzel. What is this fixation you have with things touching your butt?

Okay, fine, maybe I should have said that your waist touches your butt, but that isn't the point of my asking this question (and besides, your butt technically doesn't touch anything either; it's just interacting at short distances with other things' electrons). I am genuinely puzzled. It would be helpful if you could reply to my post with some information that could help me better understand what is happening when you sit down and sit up. After all, that is what this thread is all about.

Also, neither of these posts have even partly answered my question. I would very much appreciate it if someone who knew the answer to my question would post it.
 
  • #5
Okay, fine, maybe I should have said that your waist touches your butt, but that isn't the point of my asking this question (and besides, your butt technically doesn't touch anything either; it's just interacting at short distances with other things' electrons).

Ah, but that IS touching! I suppose the answer to your original question is that your butt doesn't stick to the chair because the atoms and molecules interact but do not form chemical bonds. Without bonding two atoms do not stick together.
 
  • #6
Drakkith said:
Ah, but that IS touching!

Technically speaking, no. Touching is when two objects are so close together that there isn't any space in between them. I guess it does actually depend on the way you define "touching," in which case, I have no right to say your wrong, but you have no right to say I'm wrong either.

Drakkith said:
because the atoms and molecules interact but do not form chemical bonds. Without bonding two atoms do not stick together.

So every single atom in your body is chemically bonded? What about when the chair turns out to be a butt-eating chair and it eats off my butt. Does that break the chemical bonds between my [STRIKE]torso[/STRIKE] waist and my butt? I thought that cutting/biting off was a physical change, but wouldn't it have to be a chemical change if it involves breaking the chemical bonds between my butt and my waist?
 
  • #7
Boundary layers, that is what separates different bodies. Generally (on metals) a layer of oxide forms which protect the bulk of metal from further reaction. Undoubtedly similar layer exist on non metals.
 
  • #8
exfret said:
Technically speaking, no. Touching is when two objects are so close together that there isn't any space in between them. I guess it does actually depend on the way you define "touching," in which case, I have no right to say your wrong, but you have no right to say I'm wrong either.

Technically speaking, yes, it is. There is no other form of 'touching'. Things do not get so close that there is no space between them. Even defining something like the size and boundaries of an atom is problematic since it relies on a probability map of where the electrons might be at any given time.

So every single atom in your body is chemically bonded?

Practically all of them. I'm sure there are a few floating around that aren't bonded. Keep in mind that your body is a complex object made up of trillions upon trillions up cells, all surrounded by a network of connective tissue and fluids, in which trillions of other things like bacteria and viruses stroll through like they own the place. In such an environment I doubt there are any quick, simple answers.

What about when the chair turns out to be a butt-eating chair and it eats off my butt. Does that break the chemical bonds between my [STRIKE]torso[/STRIKE] waist and my butt?

The simple answer is yes. However you'd have to look into everything that actually holds your body together and see how it all works to get a full understanding. Your body isn't a solid object with only one type of bond between everything. It has many different ways of staying intact and all operate differently. My knowledge on the subject is very limited, so I can't give a 100% definitive answer.

I thought that cutting/biting off was a physical change, but wouldn't it have to be a chemical change if it involves breaking the chemical bonds between my butt and my waist?

I'm not sure what the distinction is between 'physical change' and 'chemical change' is in this circumstance.
 
  • #9
The questions seem to have started with how things stay together to how they stay apart.
It's quite a big subject and a lot of the answers are more about exploring what is meant when we say that two bits are part of the same object ... what do we mean when we say that two things are touching - and so on. A lot of confusion comes from being imprecise about these things - but being precise will make for too much writing. So what we do is provide a bunch of rules for which there will be some exceptions.

Very generally, seperateness and togetherness are emergent properties of underlying electromagnetic interactions.
There is a sense in which we can say that nothing is really separate from anything else ... being careful about the definition of "really". But there is also a more immediate sense in which I like to think the table I'm sitting at is not part of me and the table owner encourages this way of thinking. A lot of this thread, therefore, is in the context of this way of thinking.We can do a lot by thinking of the common understandings and investigating what happens. i.e. a smooth surface that we see is the strong scattering region for the ambient light averaged over many detection events in our eyes and processed in the visual cortex before becoming part of our conscious awareness ... the link between physics, biology, chemistry, and consciousness being an, as yet, unsolved problem.

When we say two objects are touching, then actually measure the gap very accurately, we will discover that it is not zero ... it's just small enough for the description "touching" to make sense... usually that means the gap is too small to see with the eye, or by some, otherwise useful, measuring process.The old saw is about why one object does not pass through another ... both are made of atoms, and are mostly empty space (it goes) and there is plenty of room for the atoms to pass each other, so why can't you push your hand through the table or walk through walls?

Practically all the things we think of, in every day terms, as surface properties are about electrons ... objects like your hand and the table stay separate in normal circumstances because the electrons of your hand repel the electrons in the table ... the repulsion increases as they get closer and, classically, it gets infinite for zero separation: so there is no way you can exert enough force with just your muscles to push your hand through the table.

Something like a biological organism is basically a complicated bag of stuff, with bits and bobs all tangled up.
Every atom in your body is chemically bonded to some other atom in your body ... but not all the molecules are chemically bonded to each other, there are cells floating in fluid in your veins and arteries for example. When you get beyond chemistry it's more about which bag the stuff is in or how the fibers are wrapped around each other.

Bags contain stuff for the same reason you cannot push your hand through the table.

Some stuff is stickier than others - look up the origin of friction and adhesion: it's a whole field of study by itself - but it boils down to how the electrons are arranged close to the classical surface of the stuff. The stickiness is how fibers can get wrapped around each other without having zero separation between any of their parts.

When the killer chair eats your butt, it does not have to break chemical bonds - it just has to tear the fibers apart.
In general, this may involve breaking weak bonds and adhesion and so on just because bodies are very complicated.

And so on and on - it is a very big subject.
For more in-depth you should be reading about the theory of complex systems (chaos math for example - and cellular automata).
In these forums we can handle simpler systems like two blocks of metal being rubbed together - makes for less typing ;)
 
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  • #10
Thanks Simon, that is exactly what I wanted to say but couldn't explain.
 
  • #11
Hmm. So what about the chair? Is the wood of my chair bonded? (Really it's not a wooden chair, but it isn't a man-eating chair either). Are so many everyday objects bonded so that when they are pushed down by gravity, they don't act like a liquid and 'melt' to the floor? Why do solids retain their shape? Does every solid have a chemical bond running through itself? So, does this mean that there is a special 'solid bond' that bonds all solids together? Or is it just friction somehow acting on atoms? How would friction act on atoms? I just can't imagine a molecule or an atom acting as something other than an individual particle unless it has some special type of chemical bond to 'stick' it to something else.
 
  • #12
exfret said:
Why do solids retain their shape? Does every solid have a chemical bond running through itself? So, does this mean that there is a special 'solid bond' that bonds all solids together? Or is it just friction somehow acting on atoms? How would friction act on atoms? I just can't imagine a molecule or an atom acting as something other than an individual particle unless it has some special type of chemical bond to 'stick' it to something else.

There different types of solids, in terms of forces that keep them together.
Some are similar to chemical bonds (like the covalent crystal of diamond) other are more specific to solids (like the "metallic" bond in metals).
There are also ionic crystals where the ions are held together by electrostatic forces and van der Waals crystal with very week electric dipole forces.

I don't think that the distinction between "chemical" bonds and other types of bonds is really relevant for your question.
 
  • #13
exfret said:
Hmm. So what about the chair? Is the wood of my chair bonded? (Really it's not a wooden chair, but it isn't a man-eating chair either).

Of course. Similar to our body, there are many different types of mechanisms that give wood its strength and allow it to hold its shape. Yet all rely on different types of bonds between atoms at the very basic level.

Are so many everyday objects bonded so that when they are pushed down by gravity, they don't act like a liquid and 'melt' to the floor?

Yes. However I think it's important to understand that atoms/molecules in a liquid typically have weak bonds between themselves too. A perfect example is water. A water molecule consists of one oxygen and two hydrogen atoms bound in such a way that makes the entire molecule polar, meaning that one side is positively charged and the other side is negatively charged. This allows water molecules to have weak bonds between their positive and negative sides and is the reason water is a liquid as such a high temperature compared to many other types of compounds. If it did not have these bonds water would melt and boil at much lower temperatures than it currently does.

Why do solids retain their shape? Does every solid have a chemical bond running through itself? So, does this mean that there is a special 'solid bond' that bonds all solids together?

Some solids, such as metals and crystals, have a single type of bond between their atoms, but most have a mix of different types of bonds. This is especially true of complex objects such as wood, the human body, and your chair as a whole.
See this article for more: http://en.wikipedia.org/wiki/Bonding_in_solids

Or is it just friction somehow acting on atoms? How would friction act on atoms?

No, it's not friction. Friction is different. It is the force that resists relative motion between two objects. It would be better to make a new thread if you want to understand what friction is.

I just can't imagine a molecule or an atom acting as something other than an individual particle unless it has some special type of chemical bond to 'stick' it to something else.

You are correct. Without a bond, an atom does not act like anything else but a single atom. For example, a helium atom is very very stable and will not bond with anything else under normal circumstances. Because of this, helium does not form molecules and never partakes in chemical reactions. It is always a monatomic gas, meaning it is always found as single atoms in a gaseous state except under the most extreme of circumstances.
 
  • #14
Okay, I understand now. I thought that there would be some reason why objects stayed together that had nothing to do with chemical bonding. I hadn't realized that chemical bonding was so widespread. Just imagine, the atoms in every human are bonded (well, maybe not every atom, but most of them), especially those of Double 'O' Seven.:tongue:
 
  • #15
exfret said:
I hadn't realized that chemical bonding was so widespread. Just imagine, the atoms in every human are bonded (well, maybe not every atom, but most of them), especially those of Double 'O' Seven.:tongue:

*groans*
 
  • #16
I appreciate what has been said in this thread, but would like to add that a glue manufacturer told me that we don't really need glue to bond two flat surfaces together if the mating surfaces are perfectly flat (But in reality, we don't achieve that, usually)
 
  • #17
exfret said:
Hmm. So what about the chair? Is the wood of my chair bonded? (Really it's not a wooden chair, but it isn't a man-eating chair either). Are so many everyday objects bonded so that when they are pushed down by gravity, they don't act like a liquid and 'melt' to the floor? Why do solids retain their shape? Does every solid have a chemical bond running through itself? So, does this mean that there is a special 'solid bond' that bonds all solids together? Or is it just friction somehow acting on atoms? How would friction act on atoms? I just can't imagine a molecule or an atom acting as something other than an individual particle unless it has some special type of chemical bond to 'stick' it to something else.
Did you read my last response?
See if you can attempt an answer to your own question in those terms ... that way I can tell what you are learning and how you are thinking, and I can adjust the form of the answers to suit.

Right now it just looks like you are throwing out random questions without regard to the answers you have received so far. It can be fun just throwing questions out and getting some answers back - but the idea of these forums is to learn to find your own answers.

i.e. you have already, repeatedly, been told about the different ways that solid objects can become solid. You appear to be stuck on the idea of being "bonded" somehow, but don't seem to notice the different ways of being "bound". Did you attempt to look up the things I suggested? What did you find out?
 
  • #18
pongo38 said:
I appreciate what has been said in this thread, but would like to add that a glue manufacturer told me that we don't really need glue to bond two flat surfaces together if the mating surfaces are perfectly flat (But in reality, we don't achieve that, usually)

How does that work?
 
  • #19
@pongo & swegner99: two surfaces have to be very well matched at the atomic level to bond just from being pressed together - and wood is too varied to do that. But it is true - press two uniform "surfaces" together and they can weld together ... in, say, two lumps of metal A and B, A and B...

Glibly:
Electrons like to be close to atomic nuclei but separate from each other ... if it is hard to get an electron to move away from some place, it is said to be bonded to that place. How hard it is, is the strength of the bond.

The electrons in metal A are attracted to the atomic nuclei in A, the electrons closest to the atomic nuclei are bound only to particular nuclei, electrons farther out bind to several nuclei - effectively binding the nuclei together (look up: covalent bond) and, in a metal, these electrons can actually get shared between all the nuclei in the lump.

The shared electrons are repelled from each other - but still attracted to the bulk material, so they sit in a cloud around the "outside" of the lump.

When another lump of metal, B, gets closer, it's electrons will encounter the electrons of A before they get close enough to experience the nuclear charges deeper down. So the electron clouds repel each other... so the two lumps of metal stay apart. But you could apply a lot of force, making the two lumps come close enough together than the electrons of B can feel the attraction from the atoms of A and vice versa. If that happens you can get electrons shared between the two lumps and they stick together.

The two lumps don't have to be metals - and the exact process depends on what the material is.

The pressing-together description, above, IRL will produce a lot of heat and materials tend to melt together rather than just stick - but look up "vacuum bonding".

Something like wood is a mixture of different kinds of material all tangled up in each other so it gets quite difficult to talk about. Pressing two bits of wood together ... I'd expect either that they'd burst into flame or some resin will melt and flow making a glue. With something like your hand and the table (my example prev) I'd expect the table and the hand to break before you could diffuse the atoms of your hand through the table.

But for OPs purposes it is probably best to stick to ordinary everyday processes for ordinary everyday words.

(@swegner: see if you can also follow the advise I gave to OP ... the information had already been supplied in the thread, you just needed to apply it. If you don't try, we cannot tell where we went wrong in our answers and it makes it harder to explain it to you.)
 
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  • #20
Simon Bridge said:
Right now it just looks like you are throwing out random questions without regard to the answers you have received so far. It can be fun just throwing questions out and getting some answers back - but the idea of these forums is to learn to find your own answers.

Sorry, but I have been busy needing to do other things. I should have known that I wouldn't have much time to look into this stuff. I was just confused because I thought that cutting something in half should be a physical change, which means no chemical bonds are broken, but from what I understand from the posts on this topic, that doesn't seem to be the case. Things stick together because, in a way, they're bonded, right? It seems to me that "chemical v. physical" isn't part of the problem. So, solids usually bond through electron sharing, right? Does this mean when something turns solid, its atoms usually start to share electrons so that they become in a definite shape, or is that only in metals? I have read your replies, but I haven't looked into it much past that. I hope that that's okay.
 
  • #21
exfret said:
I was just confused because I thought that cutting something in half should be a physical change, which means no chemical bonds are broken, but from what I understand from the posts on this topic, that doesn't seem to be the case.
It doesn't have to be the case - but it can be that you just separate two halves that just happen to be very close together.

Things stick together because, in a way, they're bonded, right?
My emphasis

It seems to me that "chemical v. physical" isn't part of the problem. So, solids usually bond through electron sharing, right?
Define: "usually". Ionic bonds are pretty common.
http://en.wikipedia.org/wiki/Ionic_bond

Objects can stick together through adhesion too.

Like I said before:
... the exact process depends on what the material is.
"material properties" is a very big subject.

Does this mean when something turns solid, its atoms usually start to share electrons so that they become in a definite shape, or is that only in metals?
Metallic yeah - take a look at the kinds of bonds in solid salt or water ... also look into stuff like wax and plastics.

I have read your replies, but I haven't looked into it much past that. I hope that that's okay.
It's a good idea to somehow indicate how you have taken the replies.
Remember, nobody can see your reaction.
Read a few of the other threads and see how others do it.
 
  • #22
Simon Bridge said:
Define: "usually".

I just don't see how substances would bond in a way that doesn't involve electrons (at the atomic level). There are ionic bonds, which involve electrons switching atoms; metallic bonds, which involve electrons whizzing throughout a substance without a particular atom claiming them; and then there are covalent bonds, which involve two atoms sharing electrons (I know I said electron "sharing," but I really mean bonding involving electrons). I am sure there are other ways for atoms to bond, and there are plenty of subatomic bonds, but the world seems to be dominated by bonds involving electrons.

Simon Bridge said:
Objects can stick together through adhesion too.

Yes, but don't the two surfaces have to be solid due to some sort of electron bonding first in order for them to bond together? Also, some types of adhesion involve electron bonding:
http://en.wikipedia.org/wiki/Adhesion#Chemical_adhesion

Also, since objects are solid because of bonds, doesn't a substance have to be bonded to at least two other substances in order to ensure that all substances are bonded together? I just don't get how every solid in the world is, well, solid. Since everything can turn into a solid with enough pressure and with low enough temperatures, how is every substance able to achieve "solid-ness"?
 
  • #23
I just don't see how substances would bond in a way that doesn't involve electrons
They can't - they just don't have to share the electrons.

some types of adhesion involve electron bonding:
Yes - that is not being disputed.
The article you cite shows you different forms of adhesion.

Also, since objects are solid because of bonds, doesn't a substance have to be bonded to at least two other substances in order to ensure that all substances are bonded together?
No. Not all bonds have the same mechanism. The devil is in the details.

You also seem to be mixing up different models ... by "substance" do you mean atoms or compounds or do you mean "wood" vs "metal"?

how is every substance able to achieve "solid-ness"?
Why would anyone expect otherwise?
Just using the junior high-school particle model of matter - you can make anything a solid by stopping the particles moving around. You do that by cooling it down or by holding them tightly. That the particles in question are, at core, atoms with a distribution of charges that can be separated off just adds details to that picture... for instance, why there is a state-change at all.

Of course some things require quite extreme conditions to become "solid" - like helium. The result is that the "solid" has some odd properties which make calling the state "solid" maybe a little misleading. Look it up.

At what education lever are you trying to understand this?
 
  • #24
Simon Bridge said:
You also seem to be mixing up different models ... by "substance" do you mean atoms or compounds or do you mean "wood" vs "metal"?

Sorry for being ambiguous. I'm not trying to get into complicated things like computers and living things and wood. In this thread, I usually mean substances as in elements or compounds, and I usually refer to a 'substance' as any element or compound.

Simon Bridge said:
Why would anyone expect otherwise?
Just using the junior high-school particle model of matter - you can make anything a solid by stopping the particles moving around. You do that by cooling it down or by holding them tightly.

If you cool a material into a solid in a rectangular prism shape, and then you place it spanning a length like a bridge, then the particles won't just fall like a fluid into the river. I want to know why that is. The atom of the substance at the bottom has some force acting upon it to balance out the force of gravity. I thought that I was being told that that force came from the bonds that it had with other forces. If this isn't the case with all substances, then what is holding those atoms up? I'm just wondering what force could hold those atoms in place for every known substance in the Universe, because, like you said, you can turn anything into a solid by cooling it down or pressurizing it (or a solid-like state at least).

Simon Bridge said:
Of course some things require quite extreme conditions to become "solid" - like helium. The result is that the "solid" has some odd properties which make calling the state "solid" maybe a little misleading.

Are you referring to a BEC? Does this mean that helium has no true 'solid' state?

Simon Bridge said:
At what education lever are you trying to understand this?

I have not taken high school chemistry. I have still been able to understand what you are saying, if that is what you want to know.
 
  • #25
exfret said:
Sorry for being ambiguous. I'm not trying to get into complicated things like computers and living things and wood. In this thread, I usually mean substances as in elements or compounds, and I usually refer to a 'substance' as any element or compound.
OK - atom-atom interactions tend to be different from molecule-molecule interactions and molecule-atom interactions.

If you cool a material into a solid in a rectangular prism shape, and then you place it spanning a length like a bridge, then the particles won't just fall like a fluid into the river. I want to know why that is.
Because you have cooled it into a solid of course!
OK OK see below:

The atom of the substance at the bottom has some force acting upon it to balance out the force of gravity. I thought that I was being told that that force came from the bonds that it had with other forces.
That's right - when an atoms stay close to other atoms we say the atoms are "bonded" to each other. Some effort is required to separate them.
There are different ways that atoms may become bonded to each other.

You will notice, though, that a structure like a bridge may not be made out of a single slab of a substance - two solids may be joined by drilling holes through them and fitting a third solid through the hole ... those two solids are now bound by the third one.

What I am trying to get you to realize is the variety of possible bonds.

In previous replies you have been jumping around material types and bond types and getting confused: the confusion comes from the changes in types. A description for one will not apply to another. i.e. you talked about sharing electrons for eg ... but that's not the only way to bind two atoms.

Are you referring to a BEC? Does this mean that helium has no true 'solid' state?
Define "true solid". What would a "false solid" be like?
You didn't look up "solid helium" did you?

I have not taken high school chemistry. I have still been able to understand what you are saying, if that is what you want to know.
No - and you do not appear to be understanding me.
I don't care how far you got in school - I need to know where you want me to pitch the replies.
 
  • #26
Simon Bridge said:
OK - atom-atom interactions tend to be different from molecule-molecule interactions and molecule-atom interactions.

Well, I guess that that makes it more complicated. Anyways, if all molecules can be cooled down to a solid, then my point can still be made.


Simon Bridge said:
That's right - when an atoms stay close to other atoms we say the atoms are "bonded" to each other. Some effort is required to separate them.
There are different ways that atoms may become bonded to each other.

You will notice, though, that a structure like a bridge may not be made out of a single slab of a substance - two solids may be joined by drilling holes through them and fitting a third solid through the hole ... those two solids are now bound by the third one.

Yes, a bridge can be built in many ways, but I was not trying to change the topic to how people make bridges when I wrote that analogy. I was just trying to make it clear how the substance was placed. I am confused about the fact that every single substance has the ability to become solid (or at least nearly every single substance), so every single substance must somehow bond its atoms/molecules when it is cooled and/or pressurized. I don't understand how this is possible without some sort of "universal" bond.


Simon Bridge said:
What I am trying to get you to realize is the variety of possible bonds.

In previous replies you have been jumping around material types and bond types and getting confused: the confusion comes from the changes in types. A description for one will not apply to another. i.e. you talked about sharing electrons for eg ... but that's not the only way to bind two atoms.

I am not getting confused. Like I said, I understand what has been written. It is just that everything I am writing turns out to be more complicated than I meant it to be. This is why I was writing about the bridge scenario, yet you still tell me of the other complications that I am trying to avoid. Yes, I understand that there are many types of materials all with different types of bonds. Yes, I also understand that the variety of bonds is large. But, this is not my point.


Simon Bridge said:
Define "true solid". What would a "false solid" be like?

Nevermind about that.


Simon Bridge said:
You didn't look up "solid helium" did you?

I just looked it up and found out that helium at absolute zero at pressures under 1 atm are still non-solid. Is this what you wanted me to know?


Simon Bridge said:
No - and you do not appear to be understanding me.
I don't care how far you got in school - I need to know where you want me to pitch the replies.

What do you mean when you say, "pitch the replies"? Also, what do you mean by education level if not the classes I have taken?
 
  • #27
exfret said:
Yes, a bridge can be built in many ways, but I was not trying to change the topic to how people make bridges when I wrote that analogy. I was just trying to make it clear how the substance was placed. I am confused about the fact that every single substance has the ability to become solid (or at least nearly every single substance), so every single substance must somehow bond its atoms/molecules when it is cooled and/or pressurized. I don't understand how this is possible without some sort of "universal" bond.

This 'universal' bond is simply the electrostatic/electromagnetic interaction between charged particles forming one of the different types of possible bonds. To quote wiki:

Since opposite charges attract via a simple electromagnetic force, the negatively charged electrons that are orbiting the nucleus and the positively charged protons in the nucleus attract each other. An electron positioned between two nuclei will be attracted to both of them, and the nuclei will be attracted toward electrons in this position. This attraction constitutes the chemical bond. Due to the matter wave nature of electrons and their smaller mass, they must occupy a much larger amount of volume compared with the nuclei, and this volume occupied by the electrons keeps the atomic nuclei relatively far apart, as compared with the size of the nuclei themselves. This phenomenon limits the distance between nuclei and atoms in a bond.

If you cool a material into a solid in a rectangular prism shape, and then you place it spanning a length like a bridge, then the particles won't just fall like a fluid into the river. I want to know why that is. The atom of the substance at the bottom has some force acting upon it to balance out the force of gravity. I thought that I was being told that that force came from the bonds that it had with other forces. If this isn't the case with all substances, then what is holding those atoms up? I'm just wondering what force could hold those atoms in place for every known substance in the Universe, because, like you said, you can turn anything into a solid by cooling it down or pressurizing it (or a solid-like state at least).

To simplify it a great deal, when you cool an object down, you reduce the kinetic energy and momentum of the atoms and the subatomic particles that compose them. When you reduce their energy, it requires a smaller amount of force to hold them in place. Once you remove enough energy the atoms are unable to break away from the attractive force they are experience to and from the other atoms around them. It is at this point that they become solid. This attraction between them that locks them into place is the bond.

Note that the behavior of subatomic particles is very non-intuitive, so any full explanation of atomic/molecular bonds will be incomplete if you don't understand quantum mechanics.
 
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  • #28
As Drakkith says, the "universal" bond you are interested in is some instance of the electromagnetic interaction.
There are four fundamental forces and the theory that there is a single interaction-mechanism that explains all of them is called "grand unification". We don't have that one just at the moment so we have to content ourselves with variations.

An EM bond is just one manifestation of the EM interaction - the force that separates bound atoms can be electromagnetic as well. So it is not a universal bonding force... which is why it is called an interaction instead.

A consequence of the electromagnetic interaction may be that an electron gets shared between two ions - bringing them closer together, or it may be that one atom grabs an electron off the other and the two atoms are drawn together without sharing the electron (a bit like how my bag of candy can attract children without me having to share it ;) ).

I have been trying to get you to appreciate that this fundamental interaction manifests in different ways depending on the details - like the scale and complexity of the situation. The interaction between two ions is different from the interaction between molecules - and bulk materials behave differently again.

If you look up "cellular automata" you will see how excruciatingly simple interactions can lead to extremely complex results.

It is a big complicated Universe that gets messily fascinating very fast.
 
  • #29
Drakkith said:
To simplify it a great deal, when you cool an object down, you reduce the kinetic energy and momentum of the atoms and the subatomic particles that compose them. When you reduce their energy, it requires a smaller amount of force to hold them in place. Once you remove enough energy the atoms are unable to break away from the attractive force they are experience to and from the other atoms around them. It is at this point that they become solid. This attraction between them that locks them into place is the bond.

Ah, I see now. It is the electromagnetic force that bonds the atoms. But what happens when they get pressured? Do they simply get closer together, increasing the strength of the electromagnetic bonding force?

Simon Bridge said:
There are four fundamental forces and the theory that there is a single interaction-mechanism that explains all of them is called "grand unification". We don't have that one just at the moment so we have to content ourselves with variations.

I know what the four fundamental forces are: Strong force, which holds together the nuclei of atoms; weak force, which is what causes beta decay and positron emission in atoms; the electromagnetic force, which is the force that causes magnetism and electricity; and gravity, the weakest of all forces.

Simon Bridge said:
An EM bond is just one manifestation of the EM interaction - the force that separates bound atoms can be electromagnetic as well. So it is not a universal bonding force... which is why it is called an interaction instead.

I know; the electromagnetic force is what causes two alike charges to repel.

Simon Bridge said:
A consequence of the electromagnetic interaction may be that an electron gets shared between two ions - bringing them closer together, or it may be that one atom grabs an electron off the other and the two atoms are drawn together without sharing the electron (a bit like how my bag of candy can attract children without me having to share it ;) ).

Yes, I know about covalent and ionic bonds.

Simon Bridge said:
If you look up "cellular automata" you will see how excruciatingly simple interactions can lead to extremely complex results.

Actually, I already know what cellular automata are. I especially enjoy the Game of Life, but I enjoy seeing cellular automata related to the Prisoner's Dilemma, Rock, Paper, Scissors, and the Snowdrift game. They are all fun to watch and see what happens for various starting situations. What especially intrigues me is how a simple R-pentomino can evolve into such a chaotic pattern.
 

1. Why do objects stick together?

Objects stick together due to a force called adhesion. This force is caused by the attraction between the molecules of two different objects. The stronger the adhesion force, the more likely the objects are to stay together.

2. What keeps objects from falling apart?

Objects stay together due to a force called cohesion. This force is caused by the attraction between the molecules of the same object. Cohesion keeps objects from falling apart by creating a strong bond between the molecules.

3. How do objects stay together in space?

Objects in space stay together due to the force of gravity. Gravity is the force of attraction between two objects with mass. The larger the mass, the stronger the gravitational force, and the more likely the objects are to stay together.

4. Why do some objects stay together longer than others?

The strength of the adhesion and cohesion forces between objects play a significant role in how long they stay together. Objects with stronger adhesion and cohesion forces will stay together longer than those with weaker forces.

5. Can objects stay together without any forces?

In most cases, objects cannot stay together without any forces. Forces such as adhesion, cohesion, and gravity are necessary to keep objects together. However, in some cases, objects can stay together due to friction, which is a force that resists motion between two surfaces in contact.

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