Question

Find the quantum number 'n' corresponding to the exciting state of He⁺ ion. If on transition to the ground state that ion emits two photons in succession with wavelength 1026.7Å and 304 Å. (assume R = 1.096 × 10⁷/m).

• A. 4
• B. 6
• C. 2
• D. 1

Answer 1

Answer: (B)

6

Answer 2

$\frac{nc}{\lambda_{1}}$ + $\frac{nc}{\lambda_{2}}$ = RchZ² $\left( \frac{1}{1^{2}} - \frac{1}{n^{2}} \right)$

put l₁ = 1026.7 Å & l₁ = 304 Å

Z = 2

Calculate n, n = 6