Physical vs. Chemical Changes

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting ice, boiling water, and breaking glass.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include rusting iron, burning wood, and baking a cake.

Front

Can you give an example of a physical change?

Back

An example of a physical change is freezing water to make ice.

Front

Can you give an example of a chemical change?

Back

An example of a chemical change is the reaction of vinegar and baking soda, which produces carbon dioxide gas.

Front

What happens to the molecules during a physical change?

Back

During a physical change, the molecules may change their arrangement or state (like solid, liquid, gas) but their chemical structure remains the same.

Front

What happens to the molecules during a chemical change?

Back

During a chemical change, the molecules rearrange to form new substances with different chemical properties.

Front

Is dissolving sugar in water a physical or chemical change?

Back

Dissolving sugar in water is a physical change because the sugar can be recovered by evaporating the water.

Front

Is burning paper a physical or chemical change?

Back

Burning paper is a chemical change because it produces ash and smoke, which are new substances.

Front

What are some indicators of a chemical change?

Back

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

Front

What is the law of conservation of mass?

Back

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