I had a physics exam today in which we were presented with a model of a hydrogen atom with a single electron orbiting a single proton. We were told the radius of the "orbit" of the electron, and subsequently had to calculate the electrostatic force between the proton and the electron and the speed of the electron. Then for the last part of the question, we had to calculate the de broglie wavelength of the electron, and then the ratio of this wavelength to the circumference of the electron's orbit - i got the answer to be 1.0 to 2sf. Assuming this is the correct answer (which it may well not be), it seems to be a like a very interesting result. Can somebody perhaps explain to me if there is an underlying reason (which, if it exists, I assume to be quantum mechanical), as to why this is the case. Thanks.