Question

In a hydrogen atom,an electron undergoes transition from an energy level with n=4 to an energy level with n=2. Calculate the wavelength of the spectral line thus obtained. In which region of electromagnetic spectrum this line would be observed and what would be its colour?

Answer 1

Answer:

By Rydberg's Equation,

1/lambda = R ( 1/n1^2 - 1/n2^2)

1/ lambda = 1.097 * 10^7 ( 1/2^2 - 1/4^2)

1/ lambda = 1.097 * 10^7 {( 4 - 1 ) / 16}

1/ lambda = 1.097 * 10^7 { 3} / 16

Lambda = 16/ 3.291 * 10^7 m^-1

❇ Wavelength of spectral line, Lambda = 4.861 * 10^-7 m^-1 = 486 nm

❇ Cyan ( Blue ). Infrared spectrum.