Question

In a sample electron jumps from 5th excited state to ground state then the no of spectral lines in visible rsy

Answer 1

the right ans is 6
5-2(5-2+1)/2
6

Answer 2

Answer: 4

Given:  

Excited state is 5th orbit, then n = 5 + 1 = 6

Ground state, then n = 1 + 1 = 2

Number of spectral lines from 5th excited state to ground state i.e., from n = 6 to n = 2

                    $V_{ 1 }\quad =\quad \frac { \left( 6-2 \right) \quad \times \quad \left( 6-2+1 \right)  }{ 2 } \quad =\quad 10$

Let us calculate the spectral lines from 5th excited state to second excited state. i.e., n = 6 to n = 3

                     $V_{ 2 }\quad =\quad \frac { \left( 6-3 \right) \quad \times \quad \left( 6-3+1 \right)  }{ 2 } \quad =\quad 6$

Number of spectral lines

                     $=\quad v_{ 1 }\quad -\quad v_{ 2 }\quad \\=\quad 10\quad -\quad 6\quad \\=\quad 4$