---
title: "A sealed laboratory container initially contains a pure sample of \\(N_0\\) radioactive parent nuclei of isotope \\(X\\). Isotope \\(X\\) undergoes radioactive decay with a constant half-life \\(T_{1/2}\\) to form a stable daughter isotope \\(Y\\), and no daughter nuclei are present at time \\(t = 0\\). Which of the following graphs best represents the number of parent nuclei \\(N_X\\) (solid curve) and the number of daughter nuclei \\(N_Y\\) (dashed curve) in the container as functions of time \\(t\\)?"
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url: "https://nerd-notes.com/ubq/123568/"
date_modified: "2026-09-28T12:00:13+00:00"
---

# A sealed laboratory container initially contains a pure sample of \(N_0\) radioactive parent nuclei of isotope \(X\). Isotope \(X\) undergoes radioactive decay with a constant half-life \(T_{1/2}\) to form a stable daughter isotope \(Y\), and no daughter nuclei are present at time \(t = 0\). Which of the following graphs best represents the number of parent nuclei \(N_X\) (solid curve) and the number of daughter nuclei \(N_Y\) (dashed curve) in the container as functions of time \(t\)?

A sealed laboratory container initially contains a pure sample of \(N_0\) radioactive parent nuclei of isotope \(X\). Isotope \(X\) undergoes radioactive decay with a constant half-life \(T_{1/2}\) to form a stable daughter isotope \(Y\), and no daughter nuclei are present at time \(t = 0\). Which of the following graphs best represents the number of parent nuclei \(N_X\) (solid curve) and the number of daughter nuclei \(N_Y\) (dashed curve) in the container as functions of time \(t\)?

- **A.** Graph A
- **B.** Graph B
- **C.** Graph C
- **D.** Graph D

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123568/*