What replaced copper wires in long distance communicationas they are cheaper and less bulky than copper cables carrying the same information

Optical Fiber

Explanation:

Optical fibers have replaced copper wire in long distance communication as they are cheaper and less bulky than copper cables carrying the same information. Optical Fibers transfer information from one place to another by sending pulses of infrared light signals. Light act as carrier waves.

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.