The core principle distinguishes physical changes from chemical changes based on whether a substance's chemical identity remains invariant or transforms into new substances with different molecular formulas and properties. In the domain of chemistry, this classification relies on formal definitions where physical changes involve only alterations in state (phase), shape, or form without modifying composition, whereas chemical changes result from reactions that break existing bonds to create distinct chemical entities such as elements or compounds. This theoretical framework is fundamental to thermodynamics and kinetics by providing a binary criteria for categorizing matter's behavior during interactions like combustion, corrosion, phase transitions, and electrolysis.
The core principle distinguishes physical changes from chemical changes based on whether a substance's chemical identity remains invariant or transforms into new substances with different molecular f…