Q96 / 110 · VITEEE 2022 · Physics
What is the ground state energy of positronium? (The ground state energy of hydrogen is \(-13.6 \mathrm{eV}\))
- A\(-3.4 \mathrm{eV}\)
- Correct answerB\(-6.8 \mathrm{eV}\)
- C\(-13.6 \mathrm{eV}\)
- D\(-27.2 \mathrm{eV}\)
Solution
For positronium reduced mass \(=\frac{\mathrm{mm}}{\mathrm{m}+\mathrm{m}}\)
\(=\frac{\mathrm{m}^2}{2 \mathrm{~m}}=\frac{\mathrm{m}}{2}\)
Hence Rydberg's constant for positronium is half of that for hydrogen atom.
Hence, ground state energy for positronium
\(=-\frac{13.6}{2}=-6.8 \mathrm{eV}\)
Hence, the correct answer is option: 'B'.