Which type of change results in one or more new substances?

• A. Physical Changes
• B. Chemical Changes
• C. Physical Property
• D. Chemical Property

Answer: (B)

A chemical change is when one or more new substances are formed. This happens because bonds are broken and new bonds are created, rearranging atoms into different molecules with different identities. You’ll recognize chemical changes by signs like a color change that isn’t just due to mixing or temperature, formation of a precipitate, gas bubbles, a distinct odor, or an energy change (felt as heat release or absorption). For example, rusting turns iron into iron oxide, and burning wood yields ash, carbon dioxide, and water. In contrast, physical changes alter appearance or state without changing the substance’s identity—melting ice, cutting paper, or dissolving sugar in water—so no new substance is produced. That’s why this type of change is the one that creates new substances.