Question

If the potential energy of an H-atom in the ground state is zero then its potential energy in the first excited state will be

• A. 10.2 ev
• B. 20.4 eV
• C. 23.8 eV
• D. 27.2 eV

Answer 1

The correct option is B 20.4 eV

$PE=2\times TE+C$
$0=2\times (-13.6)+C$
$C=27eV$

So potential energy in first excited state
$=2\times TE+C=2\times (-3.4)+27.2=20.4eV$