10.2eV=λhcλ=10.2eV1245eV−nm=122.06 nm
In Franck-Hertz experiment, the first dip in the current-voltage graph for hydrogen is observed at 10.2 V. The wavelength of light emitted by hydrogen atom when excited to the first excitation level is _________ nm. (Given hc=1245eVnm,e=1.6×10−19C ).
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