In this life, three kinds of substances have been known which are very important to life. The three substances are solids, liquids, and gases. These substances will complement and complement each other so that the needs of human life can be met. Therefore, every substance can undergo physical and chemical changes. This change then becomes a natural or artificial way to meet the needs of human life.
Solids can change from a solid to a liquid and eventually to a gas. This can happen if the solid is given sufficient heat so that it can reach certain points which can cause physical and chemical changes. The same is true for liquids and gases. Changes that are made to solids, liquids, or gases are solely to meet human needs.
In natural science lessons or exact sciences, changes in matter are discussed as a property of matter. As is known, every substance has its own properties, namely:
Solids are substances whose atomic arrangement is tightly packed so that it does not allow the movement of atoms. As a result, the shape of this substance is fixed, as is its volume.
Liquid is a substance whose atomic arrangement is somewhat loose so that it allows the movement of atoms. As a result, the shape of this substance can change according to its place, but its volume remains.
Gases are substances whose atomic arrangement is very loose so that the movement of the atoms is very free. As a result, the shape of this substance can change according to its place and its volume according to its container.
Changes in the Form of Substance
Every substance that exists in this life can be influenced by environmental conditions. This influence can cause physical and chemical changes. These two kinds of changes are a condition given by a substance if it is given an external stimulus. This stimulus can be in the form of energy that is regularly given to the substance.
There are two kinds of physical changes, namely physical and chemical changes. Both of these changes cause temporary changes in the arrangement of atoms, even permanent changes. This of course gives a different effect for these substances. In this life, the changes that occur in each substance carry different effects and different purposes.
Physical Changes
Physical changes are part of physical and chemical changes which are more emphasized on the physical changes of the changing substances. This change can be said to be a temporary change. It is said to be temporary because if the reverse reaction is applied, then the substance returns to its original form.
There are many physical changes discovered and exploited in life. This is part of the physical and chemical changes that occur in matter. When water is cooled, then at a certain temperature the water solidifies into ice. When an iron rod is heated to a certain hotpoint, the iron melts.
This is a physical change because if the reverse reaction is treated, the new substance will return to its original form. Heated ice will melt. When molten iron is cooled, it becomes iron rods or solids again. This is a basic concept of exact science.
Chemical Changes
Chemical changes are part of physical and chemical changes which are more emphasized on the chemical changes of the changing substances. This change can be said to be a permanent change. It is said to be constant because if a substance has undergone a chemical change, then to return to its original state, it cannot simply carry out a reverse reaction.
This chemical change is widely used to carry out chemical reactions between substances so that the desired new substance is obtained. Chemical changes are actually part of changing the atomic structure of substances. This means that when you make a chemical change, you are actually breaking down or combining atoms of a substance to form a new substance.
Thus, in a chemical change, there is actually a physical and chemical change occurring simultaneously. You can take an example for a chemical change is paper that is burned and turns into charcoal. When it has become charcoal, then at that time there has been a decomposition of the atoms making up the wood and due to chemical reactions, what is left is charcoal.
Charcoal is difficult to turn back into paper again with the usual reverse reaction. Another example is rock carbide which is reacted with water, so acetylene gas is obtained which is flammable. This is what shows you changes in physics and chemistry or the exact sciences.
In life, physical and chemical changes are closely related to life. Every activity of life is always surrounded by these two changes. In fact, the rice eaten is the result of physical and chemical changes from the rice harvested from the rice fields. Both changes are included in the exact sciences group.