Topic: Composition and size of nucleus, atomic masses· Atoms and Nuclei

^290_82X α Y e^+ Z β^- P e^- QIn the nuclear emission stated above, the mass number and atomic number of the product Q respectively, are :

1. 286, 81

2. 280, 81

3. 286, 80

4. 288, 82

Doubtly Asked 30 Oct 2026 NEET UG 2024 neet Save WhatsApp Report

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Answer: 1. 286, 81

Key idea: \(\alpha\) emission lowers \(A\) by 4 and \(Z\) by 2; \(\beta^+\) (positron) lowers \(Z\) by 1; \(\beta^-\) (electron) raises \(Z\) by 1. The mass number does not change in \(\beta\) decay.

\(X\to Y\) (\(\alpha\)): \(A=286,\ Z=80\).
\(Y\to Z\) (\(e^+\)): \(Z=79\).
\(Z\to P\) (\(\beta^-\)): \(Z=80\).
\(P\to Q\) (\(e^-\)): \(Z=81\).

Q has mass number 286 and atomic number 81: option 1.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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^290_82X α Y e^+ Z β^- P e^- QIn the nuclear emission stated above, the mass number and atomic number of the product Q respectively, are :

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