Chemical vs. Physical Changes

A chemical change results in the formation of new substances with different properties, while a physical change alters the form or appearance of a substance without changing its chemical composition.

Blending fruits together is an example of a physical change.

The spoiling of milk is an example of a chemical change.

Hydrogen gas can be identified by a characteristic 'pop' sound when ignited.

Gallium melts into a puddle of liquid metal, demonstrating a physical change.

Common indicators of a chemical change include color change, gas production, temperature change, and the formation of a precipitate.

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Melting ice into water is an example of a physical change involving a state change.

Energy is often absorbed or released during chemical changes, which can affect the temperature and state of the substances involved.