At the behest of the science, a chemical change is he thermodynamic type process from which one or more substances, after the action of an energy factor, are converted into other substances, which in the jargon are called products.
Process in which the nature of a substance will be altered
In these processes the nature of the substance in question is altered, emblematic examples of this type of change being combustion and corrosion.
In the aforementioned chemical reaction what will be altered is the structure and composition of matter, because the initial substances will become different ones.
Meanwhile, substances can become elements, which is a type of matter made up of atoms that have the same class, or in chemical compounds, which is the substance made up of the union of two or more chemical elements.
A typical example of chemical change is one that occurs when the oxygen that inhabits our air reacts with iron and that gives rise to iron oxide, precisely composed of the elements iron and oxygen.
It should be noted that the conditions in which the chemical reaction occurs can affect the results of the products, however, after many studies it can be stated that the amounts normally remain unchanged.
Meanwhile, the concept of chemical equations It is that description in symbols of a chemical reaction.
The exclusive use attributed to them is to describe what happens in a given chemical reaction, from the beginning to the end of it.
In the equation, then, the formulas of the substances involved in the reaction will be inscribed.
On the left side the reagents will be placed and on the right side the products.
Factors that allow distinguishing this type of change and the difference with physical change
There are a series of conditions that allow warning when chemical changes occur, among them the following stand out: change in color, absorption or leakage of heat, gas segregation, appearance of a residue, alteration in odor, presence of acidity, appearance of magnetic, optical or electrical properties.
As we have already mentioned, chemical changes imply a transformation in the nature of matter, whereas when the change occurs only on the surface, remaining there, it will be a physical change.
The most concrete and forceful way to realize if we are facing a physical or chemical change is by observing if new substances appear when the change is generated, or failing that, one that already existed disappears, if this happens, then it is a change chemical, and if on the contrary there are no changes in the component substances, it will be a physical change.
Combustion and corrosion, most common chemical changes
The combustion It is a type of chemical reaction that is very common to observe and that stands out especially for presenting a very important release of energy, both in terms of light and heat and whose most popular visual manifestation is fire.
It is rigorous that in any combustion the element that burns, which will be the fuel, and on the other hand the one that causes the combustion, which is designated as oxidizer, intervene.
Among the most common fuels we find organic materials that have both oxygen and hydrogen.
And for its part, corrosion, another example of chemical change, consists of the progressive wear or destruction suffered by a material or substance.
In metals, such as iron, it is easily appreciated, because a loss or deterioration of its properties will be seen due to the interaction with the environment, which occurs naturally, and that metal oxidizes.
When the metal is porous it can be totally destroyed.
You have to be very careful with these changes because they can cause contamination or serious accidents.
Among the most common factors that trigger corrosion, we must mention the atmosphere and water that come into contact with the metal, for example, corrosion occurs more commonly in places where humidity and salt predominate, such is the case of the beach areas.
The higher the temperature, the more corrosion will be generated.
Although it cannot be avoided if the corrosion of some materials can be reduced through the use of lacquers, paints, or varnishes that protect them.
