Meaning of Physical Change
The notion of physical change has two broad meanings. On the one hand, it is used to name the variations of physical quantities that are registered in a substance. On the other hand, the idea of physical change can refer to the modifications of the body of a human being.
The changes of state of a matter are examples of physical changes. When water that is frozen is subjected to heat and melts, turning liquid, a physical change of this substance is generated. However, its chemical composition remains the same: its molecules are still made up of one oxygen atom and two hydrogen atoms. The same happens if the liquid is heated until it evaporates and becomes a gaseous state. There, another physical change of the water occurs without there being a chemical modification.
The human being makes extensive use of the physical changes of matter, both the basic ones (such as those mentioned in the previous paragraph) and the most difficult to replicate. In our homes we boil and freeze water every day, generally without being aware that we are witnessing – and causing – phenomena that belong to the realm of one of the most significant sciences for our species.
Among the most common changes of state is magnetism, a phenomenon that we can also appreciate on a day-to-day basis. It is a process that, like the change of state that leads water from being a liquid to ice or vapor, does not affect the chemical composition of iron materials.
On the other hand we have crystallization, which occurs in a large number of compounds and chemical elements, such as carbon, which can be found in various forms, such as graphite and diamond. Some of the physical properties that undergo important modifications in metals that can form crystals are ductility and strength.
The separation of certain compounds, by means of methods such as evaporation or fractional distillation, is also part of the set of physical changes, since it does not lead to an alteration in the physical composition of the compounds involved.
As for the physical change of a person, it can be seen from the evolution of their appearance. The process that leads a child to become an adolescent generates an obvious physical change: their height grows, muscles develop, hair appears in areas of the body where there were none before, etc.
A man who undergoes liposuction and who begins training in a gym three times a week is likely to achieve a major physical change in the medium term. A woman who undergoes cosmetic surgery and considerably increases the size of her bust through silicone implants also causes a physical change, in this case immediate.
Physical change can also take place for the worse, and in both cases there are two points of view from which we can analyze the situation: that of health and that of conventions. Taking drugs to shape the body can bring a good result on an aesthetic level, but at the same time damaging the body, as well as a drastic change in body weight can affect both fields.
For society in general, being overweight is synonymous with ugliness, it is a characteristic that negatively affects the appearance of a person; however, what should really matter to us is health. Any extreme can be negative, both excessive weight loss and obesity, regardless of the opinion of those who direct the aesthetic trends. Therefore, the way to assess a physical change varies according to the point of view.