Find the energy of each of the photons which (i) corresponds to light of frequency 3×1015 Hz. (ii) have a wavelength of 0.50 Å
Given:
Planck’s constant, h = 6.626 × 10−34 J s
Speed of light, c = 3.0 × 108 m s−1
(i) Photon corresponding to frequency 3 × 1015 Hz
Energy of photon:
E = hν
E = (6.626 × 10−34) × (3 × 1015)
E = 1.99 × 10−18 J
(ii) Photon having wavelength 0.50 Å
Wavelength, λ = 0.50 Å = 0.50 × 10−10 m
Energy of photon:
E = hc / λ
E = (6.626 × 10−34 × 3.0 × 108) / (0.50 × 10−10)
E = 3.98 × 10−15 J
Final Answers:
(i) Energy of photon = 1.99 × 10−18 J
(ii) Energy of photon = 3.98 × 10−15 J
Considering Bohr’s atomic model for hydrogen atom :
(A) the energy of H atom in ground state is same as energy of He+ ion in its first excited state.
(B) the energy of H atom in ground state is same as that for Li++ ion in its second excited state.
(C) the energy of H atom in its ground state is same as that of He+ ion for its ground state.
(D) the energy of He+ ion in its first excited state is same as that for Li++ ion in its ground state.