Chemistry

Problem

Which sequence correctly arranges Br⁻, Kr, and Rb⁺ in order of increasing radius? a)

\mathrm{Kr < Br^- < Rb^+}

\mathrm{Kr < Rb^+ < Br^-}

\mathrm{Rb^+ < Kr < Br^-}

\mathrm{Br^- < Kr < Rb^+}