AP EAPCET 04-Jul-2022 Shift 1 Paper

Energy of electron in nth orbit of hydrogen atom,
E=‌

−136

n2

‌eV
energy of electron in ground state (n=1),
E0=‌

−13.6

12

=−13.6‌eV
for second excited state, n=3
∴ energy of electron in H-atom in second excited state
E′=‌

−13.6

32

=−1.51‌eV
Energy required to excite the electron in hydrogen atom to second excited state
=E′−E0
‌=−1.51−(−136)=1209‌eV
‌‌≈12‌eV
Energy of ionised electron of (n=∞)H - atom.
E′′=‌

−13.6

∞

=0‌eV
energy required to ionise the electron
=E′′−E0=0−(−13.6)=13.6‌eV