Which Summertime Activity Involves Only Physical Change?

Understanding Physical and Chemical Changes

In chemistry, changes in matter can be classified into two main categories: physical changes and chemical changes. Physical changes are changes that do not alter the chemical composition of a substance, while chemical changes involve the rearrangement of atoms in a substance, resulting in the formation of new chemical compounds.

Summertime Activities and Changes

Now, let's take a look at some popular summertime activities and determine whether they involve physical or chemical changes.

This activity involves only physical changes. When you mix water and sand to build a sandcastle, you are not creating any new substances. Instead, you are simply rearranging the sand particles and compacting them together to form the sandcastle structure.

This activity involves a chemical change. When your skin is exposed to sunlight, the UV rays trigger a chemical reaction in your skin cells, leading to the production of melanin, which causes your skin to darken or tan.

This activity involves both physical and chemical changes. Chewing and swallowing the sandwich are physical changes, while the digestion process in your stomach involves chemical changes as enzymes break down the food into nutrients that can be absorbed by your body.

This activity involves a chemical change. When you light the bonfire, the wood undergoes combustion, a chemical reaction that releases heat and light energy. The wood is broken down into ash, water vapor, and carbon dioxide during the burning process.

So, the correct answer to the question is a. making a sandcastle out of water and sand. This is because water and sand is only a mixture, so they do not react with each other. All the other activities mentioned above involve chemical reactions!