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UPSC Combined Geo-Scientist

Chemist

  • 2 objective papers
  • 120 questions each
  • 2 h per paper
  • 100 + 300 marks

Prelims Paper I covers general studies.

UPSC Combined Geo-Scientist, Prelims · 2025 · Paper I, General Studies · Q21 of 120

Geo-Scientist Prelims 2025 General Studies Q21: The radius of the first stationary state orbit of hydrogen atom is

QuestionAtomic structure / Bohr model

The radius of the first stationary state orbit of hydrogen atom is

  1. (a) 5·0 Å
  2. (b) 52·9 pm
  3. (c) 5·29 pm
  4. (d) 0·529 pm

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