Physical and Chemical Changes Review

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and dissolving.

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and includes changes such as rusting, burning, and cooking.

Evidence of a chemical change includes color change, gas production, temperature change, and the formation of a precipitate.

During a physical change, the arrangement of molecules may change, but their chemical structure remains the same.

During a chemical change, the bonds between molecules break and new bonds form, resulting in new substances.

An example of a physical change is ice melting into water.

An example of a chemical change is baking a cake, where ingredients react to form a new product.

Increasing temperature can cause solids to melt into liquids and liquids to evaporate into gases. Decreasing temperature can cause gases to condense into liquids and liquids to freeze into solids.

Heat causes the molecules in water to move faster, leading to the formation of bubbles as the water boils.

A physical change does not create new substances, while a chemical change results in new substances being formed.