VKC ScienceChemistry for written exams Telegram

UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper II covers physical chemistry.

UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper II

Q14(a). Non-degenerate and six-fold levels in a cubic box

Question

For a particle confined at constant potential within a cubic box, determine the quantum numbers of (i) the lowest excited state that is not degenerate (2 marks); (ii) the lowest energy level with a degeneracy of 6 (3 marks).

Answer in brief

(i) (nx, ny, nz) = (2, 2, 2), E = 12h²/8mL²; (ii) (1, 2, 3) and its permutations, E = 14h²/8mL², g = 6.

Part of VKC Basic

Read the key points and the full model answer with VKC Basic

VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.

See what is included Already a member? Sign in

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

The handwritten model answer pages open with the VKC plan.

Coversparticle in a 3-D boxcubic boxdegeneracyquantum numbersenergy levels

All parts of Question 14