Force That Binds Atoms: H2, Electromagnetic Force?

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In summary, the forces that keep atoms together are intramolecular forces, which can be divided into metallic, ionic, polar covalent, and non-polar covalent bonds. These forces are a result of the interaction between the electrons and nuclei in the atom, which are charged. As the protons in the nucleus come closer together, the energy levels of the electrons become degenerate. However, as the protons get closer, the degeneracy is broken and there is one symmetric wave function energy level where the electrons are more likely to stay between the protons, resulting in a lower energy state. This is known as a double covalent bond. The symmetric/antisymmetric wave functions refer to the spatial wave function
  • #1
heavybuilder
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So I now understand the forces within an atom though my question is, what force(s) keeps atoms together? So let's say 2 hydrogen atoms are present. What force(s) keeps them together to make it H2? My thought it would be electromagnetic force. But hydrogen is neutral so they wouldn't attract to each other would they?
 
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  • #2
You are correct that the interaction is electromagnetic. It is a matter of how the electrons and the nuclei interact and those are charged.

Very simplified: If you have two hydrogen atoms infinitely far away from each other all energy levels of the electrons will be degenerate. As the protons come closer together, this degeneracy is broken and there will be one symmetric wave function energy level where the electrons on average will be likelier to stay between the protons that has a lower energy than the antisymmetric one. Placing both electrons in this energy level (possible due to spin) is a double covalent bond.

A similar question would be why negatively charged ions can exist.
 
  • #3
Orodruin said:
You are correct that the interaction is electromagnetic. It is a matter of how the electrons and the nuclei interact and those are charged.

Very simplified: If you have two hydrogen atoms infinitely far away from each other all energy levels of the electrons will be degenerate. As the protons come closer together, this degeneracy is broken and there will be one symmetric wave function energy level where the electrons on average will be likelier to stay between the protons that has a lower energy than the antisymmetric one. Placing both electrons in this energy level (possible due to spin) is a double covalent bond.

A similar question would be why negatively charged ions can exist.
A more 'noddy' description (a description without QM that would have satisfied a Victorian, perhaps) could be that each atom shares each electron. The attraction between each proton and each electron pulls the two protons together until their mutual repulsion balances out the attraction. This covalent bonding happens in many other molecules and describes how large molecules with chains of Carbon atoms (in particular) can exist. School Chemistry describes the bonding between some atoms of different elements as 'ionic bonding'. In that case the model is that one electron moves from one atom to the other and actually forms two ions. (Google it).
Also, Metals are held together very strongly because the outer electrons are shared by many adjacent atoms, (a form of covalent bonding, if you like). As the metal is stretched, the electrons keep pulling and they latch onto different atoms. So the metal doesn't break because other bonds are formed.
 
  • #4
Orodruin said:
Placing both electrons in this energy level (possible due to spin) is a double covalent bond.
Two electrons in a bonding orbital constitute a single covalent bond. Just one electron (as in H2+) would give a bond of order 1/2.
 
  • #5
sophiecentaur said:
A more 'noddy' description (a description without QM that would have satisfied a Victorian, perhaps) could be that each atom shares each electron. The attraction between each proton and each electron pulls the two protons together until their mutual repulsion balances out the attraction. This covalent bonding happens in many other molecules and describes how large molecules with chains of Carbon atoms (in particular) can exist. School Chemistry describes the bonding between some atoms of different elements as 'ionic bonding'. In that case the model is that one electron moves from one atom to the other and actually forms two ions. (Google it).
Also, Metals are held together very strongly because the outer electrons are shared by many adjacent atoms, (a form of covalent bonding, if you like). As the metal is stretched, the electrons keep pulling and they latch onto different atoms. So the metal doesn't break because other bonds are formed.

So no electromagnetic force but intramoleculair forces?
Which you can divide into metallic bond, ionic bond, polar covalent bond and non-polar covalent bond?
Or does intramoleculair force have anything to do with electomagnetic force?
 
  • #6
Orodruin said:
there will be one symmetric wave function energy level where the electrons on average will be likelier to stay between the protons that has a lower energy than the antisymmetric one.

Can somebody explain this? ^

And what are symmetric and unsymmetric waves?
I think I found an answer: but i still don't get what Orodruin was saying
symmetric waves: particle interchange with bosons
antisymmetric waves: particle interchange with ferminons
 
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  • #7
heavybuilder said:
I think I found an answer: but i still don't get what Orodruin was saying
symmetric waves: particle interchange with bosons
antisymmetric waves: particle interchange with ferminons
No. The symmetric/antisymmetric here refers to a parity transformation of the spatial wavefunction. In general, if you have a symmetric potential as in the case of the two protons, the wave function of the energy eigenstates will be either symmetric or anti-symmetric.

heavybuilder said:
Can somebody explain this? ^

The simplified simplified version is. The lowest energy state is one where the electrons orbit both protons. This is state has lower energy than the hydrogen atoms you would get pulling the protons apart.
 
  • #8
heavybuilder said:
So no electromagnetic force but intramoleculair forces?
Where did you get that idea? I was talking about electrons and protons. That's electrostatic (Coulomb) Force.
I'll leave @Orodruin to answer your question to him.
 

1. What is the electromagnetic force?

The electromagnetic force is a fundamental force of nature that is responsible for the interactions between electrically charged particles. It is one of the four fundamental forces, along with gravity, strong nuclear force, and weak nuclear force.

2. How does the electromagnetic force bind atoms in H2?

In H2, the electromagnetic force is responsible for the attraction between the positively charged nucleus of one hydrogen atom and the negatively charged electrons of another hydrogen atom. This force keeps the atoms together in a stable molecule.

3. Can the electromagnetic force be stronger or weaker between different atoms?

Yes, the strength of the electromagnetic force between atoms can vary depending on the charges and distances between the atoms. For example, the force between two oppositely charged ions will be stronger than the force between two neutral atoms.

4. How does the electromagnetic force contribute to chemical reactions?

The electromagnetic force plays a crucial role in chemical reactions by determining the arrangement of atoms in molecules and the strength of bonds between them. It is also responsible for the transfer of electrons between atoms, which drives many chemical reactions.

5. Can the electromagnetic force be overcome?

Yes, the electromagnetic force can be overcome by other forces such as the strong nuclear force or thermal energy. In certain conditions, such as extreme temperatures, the bonds between atoms may break due to the dominance of other forces over the electromagnetic force.

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