Which of th

Combustion of Liquefied Petroleum Gas (LPG) is not a physical change. It is a chemical change because combustion of LPG produces new substances. A lot of heat is produced along with carbon dioxide and water vapour during this reaction. It is also irreversible in nature.

Rest three are physical changes as no new products are formed; the only state of the substance changes.

Note:

During a physical change, the physical state of substance changes. A physical change does not produce a new substance although the initial and final substances appear different. A physical change is reversible.

During a chemical change the chemical composition of substance changes. A chemical change produces a new substance with new properties. Energy is either released or absorbed during a chemical change. A chemical change is irreversible.