We explain what chemical substances are, how they are classified and some examples. In addition, hazardous chemicals.
What are the chemicals?
A chemical substance or chemical species is understood as a type of matter that is chemically homogeneous and defined, that is, it has a fixed chemical composition. Depending on the context, they can be synonymous with simple substances (as opposed to compound substances), formed by atoms of a single type.
They are characterized by their particles are inseparable by any physical mechanism . However, they may undergo physical, chemical-chemical-chemical changes, when subjected to the appropriate conditions or reactions.
The changes depend on the nature of the substance, and may consist of changes in the state of aggregation (such as cooling liquid water to obtain solid ice), or transformations in the composition which Mica of it (such as the reaction between an acid and an alkali). In the latter case they become another substance.
Chemical substances were of interest to humans since they were given the task of exploring the nature of things, especially the composition of matter, identifying what they thought they were at the time. the indivisible or fundamental forms of matter.
However, as his understanding of it changed, from the ancient Greeks to modern chemistry, he has finally been able to understand when something is chemically pure and when it is composed of other identifiable substances.
Never confuse a chemical with a mixture of any kind.
It can serve you: Chemical solution
Types of chemical substances
Chemicals can be of two types, as stated before:
- Simple substances . Sometimes referred to as substances, these are indivisible forms of matter, composed of a certain number of molecules of the same chemical element, that is, chemically "pure" matter.
- Composite substances These forms of matter, on the other hand, are composed of two or more simple substances, that is, they are chemically constituted by various elements, forming a stable and fixed structure. They are usually known as "chemical compounds."
Examples of chemical substances
Some examples of substances and compounds are the following:
- Water (compound formed by hydrogen and oxygen).
- Carbon dioxide (compound formed by carbon and oxygen).
- Ozone (substance formed by oxygen molecules only).
- Graphite (substance formed by carbon molecules only).
- Glucose (a compound made up of carbon, oxygen and hydrogen molecules).
Hazardous Chemical Substances
Chemical substances have particular properties, depending on their nature and composition. This can often represent a chemical risk to the health of humans, animals or plants.
The severity of such damage will depend on the nature of the substance, its concentration and the exposure time, as well as the route of contact. It is not the same, for example, to burn the skin with an acid, than to ingest it and corrode the bowels.
Broadly speaking, hazardous chemicals can be:
- Flammable substances This is the name of those who are capable of producing large amounts of heat, that is, they can trigger fires once they have the appropriate reagent.
- Explosive substances Those substances that, in the presence of certain elements or in the face of sudden movements that cause the momentary loss of their stability, react exothermically, that is, generating large and sudden amounts of heat and energy, being able to burn and / or violate whatever is found. your surroundings.
- Corrosive substances . Substances of extreme pH (basic or acidic) that in contact with organic matter cause focused exothermic reactions, thus producing chemical burns, or in extreme cases disintegrating the organic matter they touch.
- Toxic substances Those that react in a harmful way with the substances that make up the body, triggering in it reactions that threaten the stability of life, that is, poisoning it. Depending on the substance and concentration, the level of damage can be focused or general, immediate or gradual, and can be counteracted by an antidote, or not.
- Radioactive substances It is an atomically unstable matter, which emits amounts of gamma rays or free neutrons constantly, altering the chemical constitution of the surrounding substances (ionizing radiation). They are able to poison living beings and cause them not only burns, but unpredictable genetic mutations.
- Carcinogenic substances . Those that once introduced to the body, trigger the disorderly reproduction of certain cells, that is, cause cancer.
- Mutagenic substances . Those that directly alter the DNA of living beings, unleashing unpredictable mutations that can lead to numerous diseases, and even be transmitted to the offspring.
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