Is Matter Around Us Pure ? — Science STD 9 — Question

S.No.	Differentiating Property	Physical Change	Chemical Change
1	Explanation	In a physical change, the molecules are rearranged while their actual composition remains same.	In a chemical change, the molecular composition of a substance completely changes and a new substance is formed.
2	Type of Change	Physical change is a temporary change.	Chemical change is a permanent change.
3	Energy Production	In a physical change, no energy is produced.	In a chemical change, energy is produced (heat, light, sound, etc.
4	Formation of new substance	In physical change, no new substance is formed.	A chemical change is always accompanied by one or more new substance(s).
5	Affects	Physical change affects only physical properties i.e. shape, size, etc.	Chemical change both physical and chemical properties of the substance including its composition.

Example of a change that is both chemical and physical is the burning of wood.
Another example is eating chocolate, which is both a physical change (breaking of chocolate into smaller pieces or melting of chocolate) and a chemical change (breaking of chocolate molecules into simpler molecules, etc).