This table shows experiments done by five scientists.ScientistExperimentKylecut a bar of gold in halfKatieburned paper into ashGracereacted acid and limestone together, forming carbon dioxideIsaacmelted solid aluminum, forming liquid aluminumCalebadded oxygen to metal, forming rust

A chemical change forms one or more new substances. Burning paper makes ash, acid reacting with limestone produces carbon dioxide, and oxygen reacting with metal forms rust, so Katie, Grace, and Caleb performed chemical changes. Cutting gold and melting aluminum only change their size or state, not what substances they are.

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