Question

The earth revolves around the sun in an orbit of radius 1.5 × 10¹¹ m with orbital speed 30 km/s. Find the quantum number that characterises its revolution using Bohr's model in this case (mass of earth = 6.0 × 10²⁴ kg).

State Bohr's postulates and derive an expression for the energy of electron in nth orbit in Bohr's model of hydrogen atom.

Calculate binding energy per nucleon (in MeV) of ¹²₆C. Given : m(¹²₆C) = 12.000000 u, m(¹₀n) = 1.008665 u, m(¹₁H) = 1.007825 u

(i) State three postulates of Bohr's theory of hydrogen atom. (ii) Find the angular momentum of an electron revolving in the second orbit in Bohr's hydrogen atom.