Speed All

Speed All
Why do not expect all the molecules in a gas having the same average speed?

Why do not expect all the molecules in a gas having the same average speed?

A gaseous substance that is a huge number of tiny particles that pass through large areas without crashing, then collide like billiard balls and fly off in different directions with different speeds, until the next collision. If we were to trace the path of a single molecule Gas (natural, this can be done only mentally), I would find it moving now to the left or right, far forward or backward. Sometimes moving with great speed and sometimes moves slowly. Given the chaotic nature of thermal motion of gas, must have an equal number of molecules in all directions. It should be noted, however, that these statements were statistical. They are valid on average, by which the greatest number of molecules involved the more valid. If the number of molecules is large, the deviations of the instantaneous values ​​of the mean, ie the fluctuations are negligible. Since there are 2.7 x 10 ^ 19 molecules cm cube of gas, fluctuations in the amounts per cube cm to 2 x 10 ^ (-10) with the formula f = 1 / square root any of the molecules, the value shows that it is beyond the experimental observations. This is the reason to expect that all the molecules in a gas has the same average speed. In a rarefied gas, however, we could not expect the same.