Calculate the energy emitted when electron of 1.0g atom of hydrogen undergo transition emitting the spectral line of lowest energy in the visible region of its atomic spectrum `[R_(H)=1.1xx10^(7)m^(-1)`]

Explanation

The given spectral line in the visible region, corresponds to the Balmer series, for Balmer series, `overline(v)=R_(H)[(1)/(n_(1)^(2))-(1)/(n_(2)^(2))]`
For lowest energy, `n_(1)=2 and n_(2)=3`.
`therefore (1)/(lamda)=R_(H)[(1)/(2^(2))-(1)/(3^(2))]=1.1xx10^(7)xx(5)/(36)`
the amount of energy emitted during the transition of an electron, `E=hv=hxx(c)/(lamda)=hxxcxx(1)/(lamda)`
`=6.626xx10^(-34)xx3xx10^(8)xx(1.1xx10^(7)xx(5)/(36))=3.037xx10^(-19)J`
`therefore`The energy emitted when electrons of 1gram-atom of hydrogen undergo transition`=N_(0)xxhv`
`=6.022xx10^(23)xx(3.037xx10^(-19))J=18.28xx10^(4)J=182.8kJ`.