Question

URGENT

Q. Find the wavelength of the radiation required to excite the electron in Li ++ from the first to the third orbit.
Ans. 11.4nm

PLS NOTE: I TOOK N1= 1 AND N2=3 AND GOT QRONG ANS WHY? ELABORATE

Answer 1

 (i) En = - 13.6 / n2 Z2 eV / atomFor Li2+ , Z = 3 ∴ En = - 13.6 x 9 / n2 eV / atom∴ E1 = - 13. 6 x 9 / 1 and E3 = - 13.6 x 9 / 9 = - 13. 6∆E = E3 – E1 = - 13. 6 – (- 13.6 x 9)13. 6 x 8 = 108.8 eV /atomΛ = 12400 / E (in eV) Å = 12400 / 108.8 = 114 Å(ii) The spectral line observed will be three namely 3 ⟶ 1,3⟶ 2, ⟶ 1.
I hope this is correct.