# Bohr radius for single electron orbits

1. Mar 10, 2007

### xiankai

for ions with more than one proton ie. He+, Li2+ and Be3+, doesn't the extra charge factor into the equation? because it seems only the elementary charge is http://en.wikipedia.org/wiki/Bohr_radius" [Broken], hence rendering it independent of amount of positive charge present.

Last edited by a moderator: May 2, 2017
2. Mar 10, 2007

### Staff: Mentor

Yes. For ions with a single electron but $Z$ protons, replace $e$ with $Ze$, where $e$ is the unit charge $1.60 \times 10^{-19}$ C.

Most textbooks do the derivation with hydrogen in mind, and later make the above correction for heavier, hydrogen-like ions.

3. Mar 10, 2007

### xiankai

got it. thanks for the quick reply!