Question

What are the two ways in which the physical matter can be changed?

Answer 1

Hint: The three states of matter are the three distinct physical forms that matter can exist in as they are referred to as the solid, liquid, and gaseous state. One of the other states that is predicted by many is the plasma or the Bose-Einstein condensates. Interconversion of matter refers to the change of state from one to the other. It is the process by which matter can change from one state to another and back to its original state. One important feature of this is that there is no change in its chemical composition.

Complete answer:
Matter can be changed from one state to another by heating or cooling (By changing temperature). For example, ice (a solid) is heated and it changes to water which is a liquid. This change is known as melting. If water is further heated, it changes to steam which is in the gaseous state.
Another method for achieving the change in states is by applying pressure. When we apply pressure and simultaneously reduce the temperature then the gases can be converted into liquids i.e., gases will get liquefied. This process of conversion of a gas into a liquid by increasing pressure or decreasing temperature is known as liquefaction.

Note:
Physical changes will only cause changes in the appearance of a substance, and not in its chemical composition. Chemical changes however cause a substance to change into an entirely new substance with a new chemical formula. Heating of ice to obtain water is a physical change whereas reaction of water with metal to form hydroxides and hydrogen is a chemical change.