6. An electron in a hydrogen atom is excited 1lI I ground state. Calculate the energy of an
emitted photon as it returns to n1. Find ll wavelength, and state whether or not this is in the range
of visible light. Given Find Equation(s) Solution 7. How much energy must be supplied to the
mercury atom in the ground state to raise it to n-h? a) -1.57 eV b) -10.38 ev c) -8.81 eV. d) +8.81
ev 8. An electron in a hydrogen atom falls from n 3 to n-2. The photon emitted has an energy of
a) -1.89 ev b) +1.89 eV c) 4.9 eV d) -3.4 ev 8. 9. The frequency and wavelength of a photon
whose energy is 2.86 eV are: a) 6.9x10" Hz, and 4.34x107m. b) 4.34x101" Hz, and 6.9x107m.
c) 1.89x10 Hz, and 1.58x10 m. d) 4 56x10 Hz, and 6.57x107 m
Solution
a)-1.57ev
b) energy of photon emitted= transition from n=3 to n=2
Nf= 2 and Ni=3;
E =13.6 ev× ((1/Nf^2) -(1/Ni^2))
= 13.6 ev× ((1/4)-(1/9))
=1.89 ev