I will be taking an question to help you know what is my d

Last updated: 7/4/2023

I will be taking an question to help you know what is my d oubt Let the example be A electron makes transition from 7th energy state to 2nd s tate Find number of spectral lines visible in Balmer series So here if I apply the formula An An 1 2 where An n 2 n1 then I am getting wrong answer So is there any diffe rent formula