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Indian Forest Service (Mains)

Chemistry optional

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

Paper I covers physical and inorganic chemistry.

Indian Forest Service (Mains), Chemistry optional · 2024 · Paper I

Q2(a). Most probable radius in Li²⁺

Question

Determine the most probable radius at which electron will be found when it occupies 1s orbital of Li²⁺ ion.

Answer in brief

The most probable radial distance is a₀/Z = a₀/3 = 0.1764 Å, or 17.64 pm.

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Topic notes: the hydrogen atom: Schrödinger equation in spherical coordinates, quantum numbers, radial distribution, nodes and orbital shapes, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversmost probable radiusradial probability distributionhydrogen-like ionLi2+ 1s orbitalBohr radius

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