1. Apr 10, 2007

MathematicalPhysicist

let's say we have an electron circling the nucleus (like the bohr's hydrogen atom), i dont understand why the average wrt to time of the moment of the diople is zero?
we have this equation: $$\frac{\int_{0}^{T}pdt}{T}$$
well obviously the diople, p, is constant throughout the elctron's motion, and it ahs the value p=eR where e is the electro's charge and R is the radius of motion, so unless im missing something the average should be eR, so why am i wrong here?

2. Apr 10, 2007

christianjb

The dipole is a vector.

3. Apr 10, 2007

MathematicalPhysicist

i know that it's defined as a vector which its direction is along the radius, does it mean that on the whole circle the vectors cancel eachother, obviously they do.
thanks.

4. Apr 10, 2007

christianjb

Yes. The atom has an instantaneous, but not a permanent dipole.