Question

If an electron revolving in nth excited state orbit with 1090 km/s in ${Li}^{+2}$ ion then find max possible spectral lines for the electron transition from the same excited sate to first excited state:

• A. 3
• B. 5
• C. 4
• D. 6

Answer 1

Answer: (C)

4

$V=2.18\times {10}^6\frac{z}{n}m/s$

$\therefore 1090\times {10}^3=\frac{2.18\times {10}^6\times 3}{n}$

$\Rightarrow n=6$

For $n=6$ to $n=2$ the max possible transition are $6\to 5,5\to 4,4\to 3,3\to 2$ i.e., $4$ transition

Hence, the correct option is $\text{C}$