Question

What is the wavelength (in nanometers) of a photon emitted during a transition from ni = 5 to nf = 3 state in the H atom?

Answer 1

Rydberg Equation

Apply Rydberg Formula

E = R*(1/nf^2 – 1/ni ^2)

R = -2.178*10^-18 J

Nf = final stage/level

Ni = initial stage/level

E = Energy per unit (i.e. J/photon)

E = (-2.178*10^-18)*(1/3^2 – 1/5 ^2)

E = 1.548*10^-19 J/photon

For the wavelength:

WL = h c / E

h = Planck Constant = 6.626*10^-34 J s

c = speed of particle (i.e. light) = 3*10^8 m/s

E = energy per particle J/photon

WL = (6.626*10^-34)(3*10^8)/(1.548*10^-19)

WL = 0.0000012841 m = 0.0000012841*10^9 = 1274 nm