Given that the radius of the first Bohr orbit of a hydrogen atom is

CHEMISTRY · Multi-part · CBSE · Chemistry · Structure of Atom · Structure of Atom

Problem

0.529\,\text{Å}

, answer the following for a singly-ionised helium atom (He

^{+}

, Z = 2). (i) Calculate the radius of the fourth orbit (

n = 4

) of the He

^{+}

ion. (ii) Find the speed of the electron in this orbit, expressing your answer in

\text{m s}^{-1}