Question

what is the value of total energy of an electron in hydrogen atom on the third orbit of energy of electron if in ground state is -10 electron​

Answer 1

Solution is in the attachment

Answer 2

We know that for an electron in bohr's orbit,

Potential energy = 2 x total energy

=> PE = 2 x -15 = -30 ev

Also

kinetic energy = -(Total energy)

=> KE = -(-15) = 15 ev

Now the electron has a total energy of -15ev in that orbit and -13.6 ev in ground orbit,

Hence difference in energy level of both the orbit

= -15 - (-13.6)

= -1.4 ev

According to Rydberg equation,

λ = 1240/energy difference

=> λ = 1240/1.4

=>  λ = 885.7 nm