Question

Which of the following is a physical change, rather than a chemical change?

I) gasoline burning
II) crushing salt into smaller pieces
III) ice melting

Answer 1

In the options provided, ice melting and crushing salt into smaller pieces are physical changes, while gasoline burning is a chemical change. Physical changes do not alter the chemical composition of a substance, whereas chemical changes result in the formation of new substances.

Step-by-step explanation:

The question asks to identify the physical change from a list of processes: gasoline burning, crushing salt into smaller pieces, and ice melting. Among the options, ice melting and crushing salt into smaller pieces are both examples of physical changes. In both cases, the identity of the substance does not change. When ice melts, it changes from a solid to a liquid form, but it remains water (H₂O). Crushing salt into smaller pieces changes its physical form, but not its chemical composition; it remains sodium chloride (NaCl). On the contrary, gasoline burning is a chemical change, where gasoline reacts with oxygen to form new substances like water (H₂O) and carbon dioxide (CO₂).