State the difference between a physical change and a chemical change, and list three indications that a chemical change has occurred. Which indication is most suggestive of a chemical reaction?

1 Answer
Aug 4, 2018

A physical change results in the same atoms and molecules while a chemical change results in the formation of different molecules with different properties.


Physical changes are changes in the formation or state of molecules and atoms. The arrangement of the molecules and atoms is different after the change but the chemical composition of the reactants and produces are the same.

Chemical changes are changes in the chemical bonds and composition of the the atoms and molecules. The chemical composition and formulas of the reactants and the products are different.

Significant clues as to the reaction being a chemical change are changes in color, release or absorption of a large amounts of energy. formation of a precipitant.