The force responsible for bonding in covalent molecules is the electromagnetic interaction, primarily through electrostatic attraction between electrons and atomic nuclei. Electrons in covalent bonds occupy overlapping orbitals, which lowers their energy and reduces Coulomb repulsion between nuclei. This quantum mechanical effect allows electrons to have more space and lower momentum, thus stabilizing the bond. The discussion emphasizes that the magnetic component of the electromagnetic force is not significant in this context; the primary interaction is electric.
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H2+ is a counterexample to that. The bond comes in the first place because the electron(s) forming the bond get to interact with the other nucleus, and the orbital spreads over both nuclei, lower the electron's energy. The presence of electron density in between the nuclei also helps reduce their Coulomb repulsion.Anonymous Vegetable said:To my knowledge it's to do with electrons of opposite spins and being at a lower energy with valence shells filled
I know that this is a common description, but I really don't like it. The force between the protons is not altered at all. You just get an attractive force between protons and electron(s) in addition.DrClaude said:The presence of electron density in between the nuclei also helps reduce their Coulomb repulsion.
So now I think about it, and please correct me or point out if it's a silly comment but would this be a result of the magnetic part of the electromagnetic force?mfb said:The electromagnetic interaction. Pull one nucleus, and you stretch the electron orbital a bit, the electron gets a slightly higher wavefunction amplitude between the two atoms and follows the pulled nucleus partially, that also let's the second nucleus follow.
That is a very classical description, but it works surprisingly well.
In that case, I'm still not quite understanding how the bonded electrons enable each other to follow one another due to the electromagnetic force.mfb said:I don't think it is useful to split it into components here, but it is mainly the electric part. Nothing moves very fast here.
The idea that a bond between two negative charges consists of electromagnetic interaction.mfb said:Which part of post 2 is unclear?
So how does the electromagnetic force come into this explanation sorry, if that's the force responsible?DrDu said:Covalent bonding is a quantum mechanical effect. In a bond, the electrons have more space to move than in the field of a single atom. By the uncertainty principle, this reduces their momentum and thence also their kinetic energy.
So would it be valid, to an extent to think of it in this sequence? Electron orbitals overlap forming larger area of electron density. Both nuclei are simultaneously attracted to this area holding the molecule together.mfb said:The electromagnetic force is the interaction that holds everything together. It let's a nucleus attract electrons (and electrons attract nuclei).
Anonymous Vegetable said:So would it be valid, to an extent to think of it in this sequence? Electron orbitals overlap forming larger area of electron density. Both nuclei are simultaneously attracted to this area holding the molecule together.
I realize that now sorry, the guess at magnetic involvement was more a wild guess because the word spin was mentioned.Borek said:As a first approximation it sounds OK to me. Note, that it doesn't require any magnetic part, just electrostatic attraction.
Of course it is. The attraction by the nuclei forms the basin in which the electrons are moving.Anonymous Vegetable said:So how does the electromagnetic force come into this explanation sorry, if that's the force responsible?