Neco 2023 Physics Question 9

Practice objective / multiple choice question 9 from the 2023 Neco Physics examination.

Neco 2023 Physics Objective / Multiple Choice Hard Difficulty
Question 9 NECO • 2023 • PHYSICS • objective

A radioactive isotope A decays to isotope B (half‑life 30 min) and B subsequently decays to a stable nucleus C (half‑life 10 min). Initially there are \(1.0\times10^{6}\) atoms of A and none of B. After 1.0 h: (a) How many atoms of B are present? (b) What total energy has been released if each decay of A emits 2.0 MeV and each decay of B emits 1.5 MeV? (c) What is the activity of B at that instant (in Bq)?

Answer Options

A. a) 9.3×10^4 atoms, b) 2.10×10^6 MeV (≈3.36×10⁻⁷ J), c) 1.10×10² Bq
B. a) 1.45×10^5 atoms, b) 2.80×10^6 MeV (≈3.99×10⁻⁷ J), c) 1.50×10² Bq
C. a) 8.0×10^4 atoms, b) 1.95×10^6 MeV (≈2.78×10⁻⁷ J), c) 9.0×10¹ Bq
Correct Answer D. a) 1.17×10^5 atoms, b) 2.45×10^6 MeV (≈3.92×10⁻⁷ J), c) 1.35×10² Bq
Correct Answer
D
Correct Option:
a) 1.17×10^5 atoms, b) 2.45×10^6 MeV (≈3.92×10⁻⁷ J), c) 1.35×10² Bq

About This Question

This is Neco 2023 Physics Question 9. It is one of the objective questions from the 2023 Neco Physics examination.

Difficulty level: Hard .

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