Physical changes are modifications or transformations that occur in any matter but that do not imply a modification in its nature or composition. The latter would imply a chemical change.
Physical changes occur in relation to volume, shape, or even state. That is why they can be detected from observation or by measuring the body in question.
A very simple way to recognize if any matter has undergone a physical change is that it can be reversed and returned to its previous state.
Types of physical changes
Within the physical changes we can identify them in three large groups:
Volume changes
- Dilatation. This is the change that occurs when, after the body is in contact with certain high temperatures, its size increases. Dilation can affect substances that are both in solid state as liquid and gaseous.
- Contraction. In contrast to the previous change, in this one the size of the element is reduced after coming into contact with low temperatures.
Regressive changes
Changes like these are what occurs when bodies cool down. Within these three variants can be identified:
- Condensation. When talking about this change, allusion is made to the transformation of a body that is in a solid state, to one in a liquid state.
- Solidification. As its name suggests, in this case the body passes into a solid state, when it was previously a liquid element.
- Backward sublimation. This change occurs when an element goes from being in a gaseous state to a solid.
Regressive changes
Changes like these are those that occur when bodies come into contact with high temperatures. Within these, four variants can be identified, which are detailed below:
- Evaporation. In this case, the substance changes from a liquid to a gaseous state as a consequence of the high temperatures. This phenomenon can also occur at room temperatures.
- Boiling. While in the previous case only the surface particles are affected, in this case, it reaches all of them. And it also has to do with going from a liquid to a solid state.
- Fusion. This change is observed when a substance goes from a solid state to a liquid after entering heat with high temperatures.
- Progressive sublimation. In this case, after the substance comes into contact with high temperatures, it goes from a solid to a gaseous state.
Examples of physical changes
Below is a list of physical changes as an example:
- When an ice cube is placed near the fire and it melts, it goes from a solid state to a liquid, but without losing its nature.
- When a sheet of paper is torn into several pieces.
- When the mercury found in a thermometer comes into contact with high temperatures, its size expands, but its nature does not change because of this.
- When you put water to boil in a pot, it goes from a solid to a gaseous state.
- When a glass is fogged, after a while droplets begin to form. This is as a consequence that the water vapor turns into liquid.
- When the ice cream is out of the freezer and thaws.
- When glass comes into contact with high temperatures, it becomes more malleable.
- When a piece of cheese is grated with a grater.
- When the clouds collide and it rains, the water goes from a gaseous state to a liquid.
- When a metal such as gold is melted, it goes from a solid to a liquid.
- Dissolve a tablespoon of sugar in a glass of water. Although that one dissolves, neither of the two elements can its qualities.
- When we forget a bottle of Coke in the freezer and it freezes, it goes from a liquid to a solid state.
- When there are high temperatures and the concrete in the street swells and sometimes even cracks.
- When a piece of iron is filed.
- When we leave a bottle of alcohol open and it evaporates.
- When we fill the coolers with water and put them in the freezer, we will soon have ice cubes. In this case, the water goes from a liquid to a solid state.
- When we wash our hair and then dry it with the hair dryer.
- When we break a stone into several pieces.
- When we mold a piece of plasticine.
- Over time, perfumes evaporate. That is, they go from a liquid to a gaseous state.