Polarity in Atoms: Understanding Electron Movement in Covalent Bonds

[harjot singh]

here polarity in an atom is although chemistry topic but my problem is related to QM
my question is that how electrons revolve around the covalently bonded atom where the electrostatic forces of attraction causes them to stuck at a single point. but if this assumption is wrong then correct me here and also tell me how polarity of electrons on one side of atom is possible if electrons is taken as standing waves in atom?

 

[Simon Bridge]

In QM, electrons do not revolve around atoms.
They cannot get "stuck at a single point" either.

Instead the electron will have some energy state with a spatial distribution spanning both molecules all the time.
The available stationary states can be found by solving the shrödinger equation for the combined potential of the atoms. The usual introduction to this topic investigates the H₂^+ molecular ion as the simplest case.

See: Brandes T. (2005) V.3 p39 in http://wwwitp.physik.tu-berlin.de/brandes/public_html/publications/notes05.pdf in "Lectures", from the University of Manchester.

 

[harjot singh]

In QM, electrons do not revolve around atoms.
They cannot get "stuck at a single point" either.

Instead the electron will have some energy state with a spatial distribution spanning both molecules all the time.
The available stationary states can be found by solving the shrödinger equation for the combined potential of the atoms. The usual introduction to this topic investigates the H₂^+ molecular ion as the simplest case.

See: Brandes T. (2005) V.3 p39 in http://wwwitp.physik.tu-berlin.de/brandes/public_html/publications/notes05.pdf in "Lectures", from the University of Manchester.

then explain me how polarity occurs?

 

[Simon Bridge]

As with any classical effect: Polarity occurs on average - the probability distributions do not have to be symmetrical. The various classical behaviors you are used to are emergent behaviors.

Can you give an example of polarity in a neutral atom so I know what you are talking about.

 

[harjot singh]

for example:- we see van der walls' bond formed by two molecules due to polarization?

i m talking about this polarity

 

[Simon Bridge]

Same answer.
Wan der Waals effects arise from molecules - where electrons spend more time close to one part of the molecule than other parts... on average. In QM we say that the electrons are more likely to be found in some places than others.