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Friday, 9 October

NEET UG 2021 · Physics · Question 1

NEET 2021 Physics, question 1

Question 1 of the NEET 2021 paper (code O1) is a Physics question from Nuclei. Its idea, Alpha Emission Z and A Changes, was asked only this once in NEET 2017–2026. The NTA final answer key gives option 1.

Updated 2026-10-08

Q1 · Physics

A radioactive nucleus ZAX\mathrm{^{A}_{Z}X} undergoes spontaneous decay in the sequence

ZAX→Z−1B→Z−3C→Z−2D\mathrm{^{A}_{Z}X \to {}_{Z-1}B \to {}_{Z-3}C \to {}_{Z-2}D}, where Z is the atomic number of element X. The possible decay particles in the sequence are :

  1. 1β+\beta^{+}, α\alpha, β−\beta^{-}Official answer
  2. 2β−\beta^{-}, α\alpha, β+\beta^{+}
  3. 3α\alpha, β−\beta^{-}, β+\beta^{+}
  4. 4α\alpha, β+\beta^{+}, β−\beta^{-}

Official answer: option 1 · NTA final answer key

Same idea

The only question on Alpha Emission Z and A Changes

No other NEET paper from 2017–2026 tested this exact idea.

Alpha Emission Z and A Changes: every question and how it was framed

The chapter

Nuclei in ten years of NEET

13 questions from 2017–2026, asked in 9 of 10 papers, about 1.2 a paper. Radioactive Decay alone had 9.

Chapter analysisStudy this chapterPractise this chapter

Nuclei: questions per paper

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