Bohr’s model explains the hydrogen spectrum but fails for helium mainly because
CHEMISTRY · Single correct · CBSE · Chemistry · Structure of Atom · Structure of Atom
Problem
Bohr’s model explains the hydrogen spectrum but fails for helium mainly because
(a) Bohr’s model neglects relativistic corrections which become significant for helium because its electrons move close to the speed of light.
(b) The nucleus of helium is not a point charge; its finite size invalidates the pure Coulomb potential assumed in the model.
(c) electron–electron repulsion in helium invalidates the single-electron assumption of the model.
(d) Bohr’s model requires perfectly circular orbits, but electrons in helium follow elliptical paths, so the quantisation fails.