Indian Forest Service (Mains), Chemistry optional · 2025 · Paper I
Q2(a)(ii). Box length from an emission frequency
Question
A particle of mass 9.1 × 10⁻²⁸ g in a one-dimensional box changes from n = 5 to n = 2 and emits a photon of frequency 6.0 × 10¹⁴ s⁻¹. Find the box length. Given h = 6.626 × 10⁻²⁷ erg s.
Answer in brief
The box length is 1.785 × 10⁻⁹ m, or about 17.85 Å.
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Coversparticle in a one-dimensional boxbox lengthenergy levels n²h²/8mL²emission frequency
All parts of Question 2
- 2(a)(i) Hydrogen equation in spherical coordinates10 marks
- 2(a)(ii) Box length from an emission frequency5 marks
- 2(b)(i) Lifetime and spectral uncertainty5 marks
- 2(b)(ii) Dissociation energies of dioxygen species10 marks
- 2(c)(i) Ordering molecular dipoles5 marks
- 2(c)(ii) Bonding and magnetism of B₂5 marks