Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be

Options

A. three
B. four
C. one
D. Fwo

Answer

A

Explanation

energy of ground state 13.6 eV
energy of first excited state `=- (13.6 )/(4) =- 3.4 eV `
energy of second excited state `=-(13.6 )/(9) =- 1.5 eV `
difference between ground state and 2nd excited state `=13.6 - 1.5 =12.1 eV `
so , electron can be excited upto 3rd orbit
No. of possible transition
` 1 to 2, 1 to 3, 2 to 3`
so three lines are possible .