- #1

- 2

- 0

## Homework Statement

Determine the most probable radius of an electron for a 2s hydrogenic atom.

## Homework Equations

r*=a0/Z where a0 is Bohr radius

## The Attempt at a Solution

Well, I know that the answer is ~5.2a0/Z. The book tells me that the most probable radius for hydrogen (EDIT - a 2s hydrogen shell I mean) is 5.2a0 - thus I know that the answer is simply 5.2a0/Z (275pm/Z) for the series of hydrogenic atoms. My only problem is this: I don't know how to get the coefficient of 5.2, and presumably simply getting it out of the book is not the right way to do it. I think it may have to do with taking the derivative of the wavefunction but I'm unsure...Any help would be appreciated, thanks!