Why a change in phase of matter is classified as physical change?
Phase changes from solid to liquid and from liquid to gas and from gas to plasma are pretty major changes in the physical characteristics, most importantly, changes in the arrangement and ordering of atoms. Solids are defined as crystal where there is long range order in the location of atoms or moelcules. Liquids have short range order but do not have long range order. Gases have no order at all. Plasmas have no order and have electrically charged species.
