At what temperature is the rms speed of an atom in an argon gas cylinder is equal to the rms speed of helium gas atom at `- 20^(@)C `? ( atomic mass of Ar = 39.9, of He = 4.0 )

Explanation

To find the temperature at which the root mean square (rms) speed of an argon atom is equal to the rms speed of a helium atom at -20°C, we can follow these steps:

### Step 1: Convert the temperature of helium from Celsius to Kelvin
The formula to convert Celsius to Kelvin is:
\[ T(K) = T(°C) + 273 \]

Given that the temperature of helium is -20°C:
\[ T_{He} = -20 + 273 = 253 \, K \]
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