When electrons jump from 3rd orbit to 2nd orbit, how many field lines can be emitted by the atom?

Answer 1

Formula is: (n2-n1)(n2-n1+1)/2
Where
n2=higher shell from where electron makes transistion
n1=lower energy shell

So answer is (3-2)*(3-2+1)/2
=> 1*2/2
=> 1

Answer: 1