## the r power

sylvie_1D
Posts: 31
Joined: Fri Apr 06, 2018 11:04 am

### the r power

Hi I am confused as to where the powers of the "r" value originate from in the potential energy formulas for dipole dipole interactions and dipole induced dipole interactions. Does it have something to do with the rotation or the seperations of the atoms?

SammiOrsini_1B
Posts: 45
Joined: Fri Apr 06, 2018 11:04 am

### Re: the r power

i think r represents the distance between the interacting particles

Miya Lopez 1I
Posts: 62
Joined: Tue Nov 14, 2017 3:00 am
Been upvoted: 1 time

### Re: the r power

r is the distance between the atoms or molecules, and in the textbook on page 193 it states that

"It turns out that the potential energy varies as the sixth power of the distance between the molecules... Doubling the separation of polar molecules reduces the strength of the interaction by a factor of 2^6=64, and so the dipole-dipole interactions between rotating molecules have a significant effect only when the molecules are very close"

So I believe it is raised to the 6th power because of the variation of the rotating atoms/molecules. Hope this helps.