Question

Indicate whether energy is emitted or absorbed when the following electronic transitions occur in hydrogen. Calculate the wavelength of the energy absorbed or emitted where indicated. R - 1.097 x 107 m-1 (a) from n = 4 ton - 5 emitted O absorbed Wavelength of radiation: (b) from an orbit of radius 4.77 A to one of radius 0.53 A emitted absorbed (c) from the n = 5 to the n = 7 state. emitted absorbed Wavelength of radiation:

Answer 1

(a)

When an electron is jumped from lower energy state (lower n value) to higher energy state, the energy will be absorbed. And vice versa Transition is 4 to 5 (energy is absorbed in this transition) ni = 4 n = 5 Given that the Balmer-Rydberg equation is n2 = 5 and n = 4 R = 1.097 x 107 m-1 -12 = =1.97x10 mº [ 1 ] =#=1.07x10°m" (16 25] ===1.097x10%m-+x0.0225 = 246825 m-- 1 1 = 4.051x10 246825 m - 1 Ï m a = 4051x10 m = 4051 nm

(a) Energy is absorbed. Wavelength = 4051 nm (b) Radius of orbit is larger, that is the orbit is the higher energy state So, the energy is emitted in this transition

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When an electron is jumped from lower energy state (lower n value) to higher energy state, the energy will be absorbed. And vice versa Transition is 5 to 7 (energy is absorbed in this transition) ni = 5 n = 7 Given that the Balmer-Rydberg equation is -=R2 14 n n2 = 7 and n = 5 R = 1.097 x 107 m-1 12 = =1.097310?m"[ 5 ] ==1.097x10m 25 ===1.097x10’m-+x0.019592 = 214922.4 m-- 1 Ï 214922.4 m-1 = 4.653x10-ºm 2 = 4653x10-ºm = 4653 nm c) Energy is absorbed. Wavelength = 4653 nm