Question

Let E_n = `(-1)/(8ε_0^2) (me^4)/(n^2h^2)` be the energy of the nth level of H-atom. If all the H-atoms are in the ground state and radiation of frequency (E₂ - E₁)/h falls on it ______.

1. it will not be absorbed at all.
2. some of atoms will move to the first excited state.
3. all atoms will be excited to the n = 2 state.
4. no atoms will make a transition to the n = 3 state.

पर्याय

• b and c

• a and c

• b and d

• c and d

Answer 1

b and d

Explanation:

Let E₂ and E₁ be the energy corresponding to n = 2 and n = 1 respectively. If radiation of energy ∆E = (E₂ – E₁) = hf incident on a sample where all the H-atoms are in the ground state, according to the Bohr model some of the atoms will move to the first excited state. As this energy is not sufficient for the transition from n = 1 to n = 3, hence no atoms will make a transition to the n = 3 state.