The kinetic energy of an electron in the first orbit of He⁺ is 4.36 × 10⁻¹⁸ J. What is its velocity? (mₑ = 9.1 × 10⁻³¹ k
v = √(2KE/m) ≈ 3.096×10⁶ m s⁻¹.
Ref: NCERT Class 11 Chemistry > Chapter 2: Structure of Atom > Topic: Quantum Numbers - Principal Azimuthal Magnetic Spin