What are examples of physical changes in matter?

Physical changes in matter include melting, freezing, evaporation, condensation, sublimation, and deposition.

Physical changes are transformations that do not alter the chemical composition of a substance. They are usually reversible and involve changes in the state or appearance of matter. Let's look at some examples.

Melting is a physical change where a solid turns into a liquid. This happens when the temperature of the solid increases to its melting point. For instance, when you heat ice, it melts into water.

Freezing, on the other hand, is the process where a liquid turns into a solid. This occurs when the temperature of the liquid decreases to its freezing point. An example of this is when water turns into ice in a freezer.

Evaporation is another physical change where a liquid turns into a gas. This happens when the liquid is heated to its boiling point or when it is exposed to air. For example, when you boil water, it evaporates into steam.

Condensation is the opposite of evaporation. It is the process where a gas turns into a liquid. This occurs when the temperature of the gas decreases to its condensation point. An example of this is when steam cools down and turns into water droplets.

Sublimation is a physical change where a solid turns directly into a gas, bypassing the liquid state. This happens under certain temperature and pressure conditions. An example of this is when dry ice (solid carbon dioxide) sublimates into carbon dioxide gas.

Deposition is the reverse of sublimation. It is the process where a gas turns directly into a solid, bypassing the liquid state. This also occurs under certain temperature and pressure conditions. An example of this is when water vapour in the air forms frost on a cold window.

Remember, in all these physical changes, the substance remains the same. It's only the state or appearance that changes.