Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes cause a substance to change into an entirely substance with a new chemical formula.
Chemical Change- Chemical changes occur when a substance mixes with another to create a new substance, a process known as chemical synthesis, or when a substance decomposes into two or more distinct substances, a process known as chemical decomposition. These processes are known as chemical reactions, and they are usually irreversible unless they are accompanied by more chemical reactions.
Physical Change- A physical change to a sample of matter occurs when some of the material's properties change but the matter's identity does not. The original shape of matter can be restored by a reversible physical transition. The original form cannot be revived after a permanent physical transition.
