---
title: "Two radioactive samples, Sample X and Sample Y, each have an initial mass of \\(10\\text{ g}\\). Sample X has a molar mass of \\(100\\text{ g/mol}\\) and a half-life of \\(2\\text{ hours}\\), while Sample Y has a molar mass of \\(200\\text{ g/mol}\\) and a half-life of \\(4\\text{ hours}\\). Let \\(A_1\\) and \\(A_2\\) be the initial decay activities of Sample X and Sample Y at \\(t = 0\\text{ hours}\\), respectively, and let \\(A_3\\) and \\(A_4\\) be their activities at \\(t = 4\\text{ hours}\\), respectively. Which of the following correctly ranks the four activities?"
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url: "https://nerd-notes.com/ubq/123491/"
date_modified: "2026-09-28T11:59:55+00:00"
---

# Two radioactive samples, Sample X and Sample Y, each have an initial mass of \(10\text{ g}\). Sample X has a molar mass of \(100\text{ g/mol}\) and a half-life of \(2\text{ hours}\), while Sample Y has a molar mass of \(200\text{ g/mol}\) and a half-life of \(4\text{ hours}\). Let \(A_1\) and \(A_2\) be the initial decay activities of Sample X and Sample Y at \(t = 0\text{ hours}\), respectively, and let \(A_3\) and \(A_4\) be their activities at \(t = 4\text{ hours}\), respectively. Which of the following correctly ranks the four activities?

Two radioactive samples, Sample X and Sample Y, each have an initial mass of \(10\text{ g}\). Sample X has a molar mass of \(100\text{ g/mol}\) and a half-life of \(2\text{ hours}\), while Sample Y has a molar mass of \(200\text{ g/mol}\) and a half-life of \(4\text{ hours}\). Let \(A_1\) and \(A_2\) be the initial decay activities of Sample X and Sample Y at \(t = 0\text{ hours}\), respectively, and let \(A_3\) and \(A_4\) be their activities at \(t = 4\text{ hours}\), respectively. Which of the following correctly ranks the four activities?

- **A.** \(A_1 > A_2 > A_3 = A_4\)
- **B.** \(A_1 > A_3 > A_2 > A_4\)
- **C.** \(A_1 > A_2 = A_3 > A_4\)
- **D.** \(A_1 > A_2 > A_4 > A_3\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123491/*