How is temperature related to the motions of molecules

The amount of molecular moment is temperature. The more excited the particles are and the more they move and bounce off each other dictates the temperature. For ex. in "absolute zero" kelvin there is zero molecular movement. While 1000 kelvin there is a blur of activity as particles collide and bounce of one another constantly.

Closing a ring restricts the rotation around individual car bon carbon bonds hope it will you !