Question

Plaiting a copper ring with gold is electric energy liberated or absorbed?

Answer 1

Answer:

All the changes in nature is divided into physical changes and chemical changes. During a physical change, only a change in the arrangement of molecules occurs. Hence it can be easily brought back to its original state. In the case of chemical changes, new molecules are formed.

The alkali formed by the reaction of sodium with water is sodium hydroxide. Because of its basic nature it becomes pink colour when phenolphthalein is added to it.

In the reaction of magnesium burns in air heat and light are produced.