`1.8 g` of hydrogen is excite by irradiation. The study of spectra indicated that `27 %` of the atoms are in the first excite state, `15 %` of the aton in the second excited, and the rest in the ground state. The ground stat, ionization energy of hydrogen atom is `21.4 xx 10^(-12)`ergs.
The number of atoms present in the second excited state is

Options

A. `1.61 xx 10^(23)`
B. `0.805 xx 10^(23)`
C. `2.92 xx 10^(23)`
D. `1.46 xx 10^(23)`

Answer

C

Explanation

Number of atoms in the second excited state
`N_(2) = (N_(av))/(M) xx m xx (15)/(100)`
`= (6.023 xx 10^(23))/(1.008) xx 1.8 xx (15)/(100) = 1.61 xx 10^(23)`
In the first exciting state
`N_(1) = (N_(av))/(M) m xx (27)/(100) = 2.9 xx 10^(23)`