Line spectra from all regions of the electromagnetic spectrum, including the paschen series of infrared lines for hydrogen, are used by astronomers to identify elements present in the atmospheres of stars. calculate the wavelength of the photon emitted when the hydrogen atom undergoes a transition from n = 5 to n = 3. (r = 2.18 × 10–18 j)

λ = 3.4 × 10^18m

Explanation:using Rydberg equation:

1/λ = RH •Z^2[ (1/n1) - (1/n2) ]

RH = Rydberg constant = 2.18x 10^-18j)

n1 and n2 = energy levels (n2 >n1)

Z = atomic number = 4

Substitute

1/λ = 2.18x 10^-18• [ (1/3) - (1/5) }

λ = 3.4 × 10^18m

found in the nucleus

has mass of one amu

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