Avibrating simple pendulum does not produce any sound why?

The shorter a pendulum is, the faster it swings.  If it swings faster than about 20 swings per second, it'll produce a sound that your ears can hear.  That would be a pendulum that's something like 0.00065 CM long !  Good luck with your construction.

see earlier

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.