# Kinetic theory of gases

1. Nov 22, 2005

### abstrkt

Two gas cylinders are identical. One contains the monatomic gas argon (Ar), and the other contains an equal mass of the monatomic gas radon (Rn). The pressures in the cylinders are the same, but the temperatures are different. Determine the ratio KEAvg,radon / KEAvg,argon of the average kinetic energy of a radon atom to the average kinetic energy of a argon atom.

I was thinking since P = NMV^2/3L^3 to set that equal to each other for the same pressure, but im lost on how to approach it from there. Any help will be appreciated. Thanks.

2. Nov 22, 2005

### Physics Monkey

From the kinetic theory we have $$P V = \frac{2}{3} E$$ for monatomic ideal gases (a pretty good approximation for the noble gases). The answer is one step way.