In the chemical bond article, Wikipedia states that due to the matter wave nature of electrons and their smaller mass, they occupy a very much larger amount of volume compared with the nuclei.

 

But why is that? Why do electrons occupy a very much larger volume than the nuclei because of their smaller mass? What does their mass have to do with the volume they occupy?

deBroglie wavelength is h/p. For a given speed, small mass means small momentum

deBroglie wavelength is h/p. For a given speed, small mass means small momentum

 

But how is this related to volume?

Waves are three-dimensional.

[math]\textnormal{Volume} \approx \left(\frac{h}{p} \right)^{3}[/math]

 

Another useful concept is the Compton wavelength.

 

[math]\lambda_{Compton} = \frac{h}{mc}[/math].

 

This gives the "smallest possible" radius of an electron. Really, you should think of it as the scale at which quantum effects of the electromagnetic field really kick in.

In the chemical bond article, Wikipedia states that due to the matter wave nature of electrons and their smaller mass, they occupy a very much larger amount of volume compared with the nuclei.

 

But why is that? Why do electrons occupy a very much larger volume than the nuclei because of their smaller mass? What does their mass have to do with the volume they occupy?

 

It is so in atoms. Look at Hydrogen atom. Both the electron and nucleus "turn around" the atomic center of mass there. As the lectron is lighter, its orbit is larger in the ratio Me/Mp to the nucleus orbit size. In quantum mechanics instead of orbits there are charge "clouds" bu the size ratio is tha same.

 

Another thing is in molecules and condensed (solid) state. There the nuclei oscillate around their equilibrium positions with much larger amplitude - it may attain the inter-atomic size. In a solid state the positive charge is also much widerl "smeared" than in an isolated atom, to be exact.