1. The problem statement, all variables and given/known data The number density in a container of argon gas is 2.00 X 10^25. The atoms are moving with an rms speed of 455 m/s. What is the pressure inside the container? 2. Relevant equations V rms = sqrt( (3)(k)(T) / m) P = F/A = (1/3)(N/V)(m)(v^2 rms) 3. The attempt at a solution I have tried manipulating all the equations to somehow find the pressure, but have been unsuccessful. I seem to have all the variables except the mass. So i assume i need to get the mass somehow, any ideas? Thanks.