Question

After time in the refrigerator a pickle jar (or any other glass jar with a metal lid) is often very hard to open. The lid seems much tighter than expected. a well-known trick to open the jar is to run it under hot water for a few seconds. explain why?

Answer 1

Explanation--->>> As the metal lid is the group of tiny molecules that are very tightly together. When the metal lid is cold these molecules are close to each other and they do not have enough energy to stay away from each other. But when we put warm/hot water over them, the water supply the heat to the jar lid and make vibrations in the molecules. With the more energy, more they will move and their bonds will become weaker. This makes the molecules spread out and so the lid will get bigger. So the water warms the jar lid which changes the density and thus changes its size, which makes easy to open.