Q. 195.0( 1 Vote )

Positronium is just like a H-atom with the proton replaced by the positively charged anti-particle of the electron (called the positron which is as massive as the electron). What would be the ground state energy of positronium?

Answer :

(note: the question is based on the concept of reduced mass)

Now from the energy formula of nth electron, we have,


where n is nth orbit

h is Planck’s constant,

m is reduced mass of electron and nucleus system

in permittivity in vacuum

is the energy of the electron in nth orbit

In the above Bohr’s formula because the electron experiences an electric force due to nucleus and by newton’s second law there is a reaction force on the nucleus due to electron , actually both nucleus and electron tend to revolve around their center of mass and thus we use concept of reduced mass given by,

For Hydrogen atom,

( )

For positronium atom,


For positronium,

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Bohr's Atomic ModelBohr's Atomic ModelBohr's Atomic Model46 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses