Find the energy released (in erg) when `2.0 g` atom of hydrogen undergoes transition giving a spectral line of the lowest energy in the visible region of its atomic spectra

Answer

A, B, C

Explanation

For H atom ,the wspectrum lines in visible region corresponding to Balmer lines of `n_(2) = 2` Now, for lower energy photon, the required transition will be from `3 rarr 2` Using the relation for `Delta E`
`Delta E = 2.178 xx 10^(-18) (1)^(2)((1)/(2^(2)) - (1)/(3^(2))) (1)/("atom")`
Now the `2.0 g `atom , the energy relation will be
`E = (2 xx 6.023 xx 10^(23)) xx 2.18 xx 10^(-18) ((5)/(36)) J`
`= 3.63 xx 10^(5) J = 3.63 xx 10^(12) erg`