HELP!!!!!!!!!急!!點解duration of

Q: 解duration of each collision with the wall is neglible compared with the time between successive collision??

Gas molecules are movigng at high speed and the collisions are elastic. When a high speed particle impinge onto a surface, it will rebound almost instantly. Hence, the very short duration of contact of the molecule with the container wall is generally much less than the time of flight from one wall to the other.

Q: 同埋denity of real gas is low??TX

Your question is unclear. I suppose you want to ask why a low density real gas behaves like an ideal gas.

In a low density gas, the separation of moelcules are large. As such, the assumptions made in an ideal gas, like there is no intermolecular attractive between molecules, the size of molecules are negligible comared with the volume of gas etc, can be valid.