Which mixtures cannot be separated by magnet?

In a closed or isolated system , matter can not be created or destroyed. it can change forms but is conserved true or false

How does a noncompetitive inhibitor reduce an enzyme’s activity?

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?