Chapter 11, Problem 11.31E

Compare the mass of the electron, $m_e$, with (a) the reduced mass of a hydrogen atom; (b) the reduced mass of a deuterium atom $\left(\text{deuterium}{=}^2\text{H}\right)$; (c) the reduced mass of a carbon $-12$ atom having a $+5$ charge, that is, ${\text{C}}^{5+}$. Suggest a conclusion to the trend presented by parts a-c.