Science
posted by Carolyn .
If oxygen, Carbon dioxide, and xenon gases are heated at 500k with a probable particle speed of 1094 and an average particle speed of 1234, what id the mass of an atom or molcule for each?

You need dimensions for the particle speeds. I assume they are in m/s.
You do not need to know both the average and the most probable speed. They are related by a constant factor.
You list three species but give only two average speeds. There will be different average speeds for each species.
The formula for the most probable speed can be found at
http://en.wikipedia.org/wiki/Maxwell%E2%80%93Boltzmann_distribution 
This is all the information I have that is in the question given to me. The speeds are all most probable particle speed ms & Average particle speed ms.

The site you referred me to is useless when you don't know how to do this kind of math. Thnaks for your help though,