An electron in the third orbit of a hydrogen atom has a velocity of 7.3 × 10⁵ m s⁻¹. What is its de Broglie wavelength?
λ = h/(mv) ≈ 9.98×10⁻¹⁰ m.
Ref: NCERT Class 11 Chemistry > Chapter 2: Structure of Atom > Topic: Quantum Mechanical Model - de Broglie Heisenberg and Schrodinger