MHT CET202520 Apr 2025Morning ShiftChemistryStructure of AtomActual
Calculate the energy associated with third orbit of He ⁺ .
Options
- A-4.8 10⁻¹⁹ ~J
- B-1.45 10⁻¹⁹ ~J
- C-19.36 10⁻¹⁹ ~J
- D-9.69 10⁻¹⁹ ~J
Correct answer
D. -9.69 10⁻¹⁹ ~J
Step-by-step solution
The energy of an electron in the n th orbit of a hydrogen-like atom is given by E_n = -2.18 10⁻¹⁸ Z^2 n^2 J/atom. For He ⁺ , Z = 2 and n = 3 . Substituting these values: E₃ = -2.18 10⁻¹⁸ 4 9 = -9.69 10⁻¹⁹ J. This matches option D from the choices provided.