Calculate kinetic energy/ speed per particle at given temperature

[Edi]

How to calculate kinetic energy/ speed per particle (atom, ion, electron, molecule.. the AVERAGE kinetic energy stays the same, but the speed differs, as there are different masses.. ) at given temperature?

 

[hylander4]

Are these particles part of an ideal gas?

 

[Edi]

ahh, good question. Forgot about "states of matter" .. well, I'm mostly thinking about a solid, but an ideal gas should be fine - I just need some approximates.
.. but what about electrons in a metal? Metal is a solid (most of them, at room temperature, at least) but it has electrons that are sort of free and fizz around - how to calculate their energy?