Question

An electron in hydrogen atom after absorbing a photon jumps from energy state n1 to n2. Then it returns to ground state after emitting six different wavelengths in emission spectrum. The energy of the emitted photons is either equal to less than or greater than the absorbed photons. Then n1 and n2 are

Answer 1

no. of spectral lines= (n2-n1)(n2-n1+1)/2

here n1=1 becoz it's mentioned in the question that it came back to the ground state.....

so no. of spectral lines= n2(n2-1)/2

and it's given in question that the no. of spectral lines=6

then,

6 = n2(n2-1)/2

12=n2^2-n2

solve this quadratic equation....

you will get n2=4 and n2= -3

and n can not be negative here so answer should be n2=4

n1=1