CGPET 2021 Solved Paper

Since the energy required to excite the electron energy levels n1 to n2 revolving round the nucleus is given by
En2−En1=∆E=13.6[

1

n12

−

1

n22

](in‌eV)
The energy required to excite the electron from ground state (n1=1) to second excited state (n=3) is given as
⇒ ∆E=13.6[

1

(1)2

−

1

(3)2

]
⇒ ∆E=12.09‌eV