Find the wavelength of the radiation required to excite the electron in Li++ from the first to the third Bohr orbit. You may need to use the constant hc = 1242 eV.nm.
The correct option is B 11.4 nm
So I have to give sufficient energy to excite an electron from the 1st orbit of Li++ ion to 3rd. So what is the energy of Li++ ion in the ground state.
Z = 3, n = 1
E1 = 9 × (-13.6) eV.
Similarly if I give it sufficient energy and the electron reaches 3rd orbit then the energy of the ion will be
Z = 3, n = 3
So the energy that would be required to achieve it should be.
Now the wavelength of this light of energy 108.8 eV could be found by .....
I know hcλ.
hcλ = 108.8
λ = 11.4 nm