RMS Speed Comparison: Argon vs Helium
This simulation visualizes the root mean square (RMS) speed of argon and helium atoms at different temperatures. Adjust the temperatures to find when their RMS speeds match.
Helium Gas
Argon Gas
Physics Explanation
The root mean square (RMS) speed of gas molecules is given by:
vrms = √(3RT/M)
Where:
- R = universal gas constant (8.314 J/mol·K)
- T = absolute temperature (Kelvin)
- M = molar mass of the gas (kg/mol)
For the RMS speeds to be equal: √(3RTHe/MHe) = √(3RTAr/MAr)
This simplifies to: TAr = THe × (MAr/MHe)
With MAr = 39.9 u and MHe = 4.0 u, the temperature ratio is 39.9/4.0 ≈ 9.975
