The ratio of the angular momentum of an electron in the fifth orbit of H to the third orbit of He⁺ is: (h = 6.626 × 10⁻³
L₅(H) = 5h/2π, L₃(He⁺) = 3h/2π. Ratio = 5/3 ≈ 1.667.
Ref: NCERT Class 11 Chemistry > Chapter 2: Structure of Atom > Topic: Electronic Configuration - Aufbau Pauli Hund and Stability