---
title: "A rigid, sealed container holds a mixture of helium gas (molar mass \\(4\\text{ g/mol}\\)) and neon gas (molar mass \\(20\\text{ g/mol}\\)) at thermal equilibrium. Which of the following correctly compares the average translational kinetic energy \\(K_{\\text{avg}}\\text{ }\\) and the root-mean-square speed \\(v_{\\text{rms}}\\text{ }\\) of the helium atoms to those of the neon atoms?"
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url: "https://nerd-notes.com/ubq/116137/"
date_modified: "2026-08-03T11:45:57+00:00"
---

# A rigid, sealed container holds a mixture of helium gas (molar mass \(4\text{ g/mol}\)) and neon gas (molar mass \(20\text{ g/mol}\)) at thermal equilibrium. Which of the following correctly compares the average translational kinetic energy \(K_{\text{avg}}\text{ }\) and the root-mean-square speed \(v_{\text{rms}}\text{ }\) of the helium atoms to those of the neon atoms?

A rigid, sealed container holds a mixture of helium gas (molar mass \(4\text{ g/mol}\)) and neon gas (molar mass \(20\text{ g/mol}\)) at thermal equilibrium. Which of the following correctly compares the average translational kinetic energy \(K_{\text{avg}}\text{ }\) and the root-mean-square speed \(v_{\text{rms}}\text{ }\) of the helium atoms to those of the neon atoms?

- **A.** \(K_{\text{He}} > K_{\text{Ne}}\text{ }\) and \(v_{\text{He}} > v_{\text{Ne}}\text{ }\)
- **B.** \(K_{\text{He}} > K_{\text{Ne}}\text{ }\) and \(v_{\text{He}} = v_{\text{Ne}}\text{ }\)
- **C.** \(K_{\text{He}} = K_{\text{Ne}}\text{ }\) and \(v_{\text{He}} > v_{\text{Ne}}\text{ }\)
- **D.** \(K_{\text{He}} = K_{\text{Ne}}\text{ }\) and \(v_{\text{He}} < v_{\text{Ne}}\text{ }\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/116137/*