Meaning of Physical and Chemical Changes - JSS2 Basic science Lesson Note

Physical changes involve alterations in the physical state or appearance of a substance without changing its chemical composition. Examples include changes in shape, size, state of matter (solid, liquid, gas), or phase transitions (melting, freezing, vaporization).

Chemical changes, on the other hand, involve the formation of new substances with different chemical compositions. This usually involves the breaking and forming of chemical bonds. Examples include combustion, oxidation, and decomposition reactions.