A chemical substance It is all matter that has a defined chemical composition and whose constituent elements cannot be separated by any physical means. A chemical substance is the result of the combination of chemical elements and is made up of molecules, form units and atoms. For instance: water, ozone, sugar.
Chemicals occur in all States of the material: solid, liquid and gaseous. These substances are found in cosmetics, food, beverages, medicines. For instance: sodium fluoride in toothpaste, sodium chloride in table salt. Some substances can be harmful to human health, such as a poison or nicotine in cigarettes.
The term chemical substance appeared at the end of the century XVIII thanks to the works of the French chemist and pharmacist, Joseph Louis Proust.
Pure chemicals (which cannot be separated into other substances by any physical means) are distinguished from mixtures, which are combinations of two or more substances without chemically reacting.
Types of Chemicals
- Simple substances. Substances that are made up of one or more atoms of the same chemical element. Its atomic composition can change in terms of the number of atoms, but not in terms of the type of element. For instance: ozone (O3), whose molecule is made up of three oxygen atoms.
- Compound or compound substances. Substances that are made up of two or more different elements. They are formed through chemical reactions. All the elements of the periodic table can combine to form compound substances and these cannot be separated by physical processes. For instance: the water (H2O), whose molecule is made up of hydrogen and oxygen. There are organic and inorganic compounds.
Compound types
- Organic compounds. Substances composed mainly of carbon atoms. They exist in all living beings and in some non-living beings. They can become inorganic through certain chemical reactions. For instance: cellulose[C6H10O5]n).
- Inorganic compounds. Substances that do not contain carbon or that carbon is not its main component. Among them is any lifeless substance. For instance: sodium bicarbonate (NaHCO3). Some inorganic elements can become organic.
Examples of chemicals
Simple substances
- Ozone (O3)
- Dioxygen (O2)
- Dihydrogen (H2)
- Dichloro (Cl2)
- Diamond (C)
- Copper (Cu)
- Dibromo (Br2)
- Iron (Fe)
- Potassium (K)
- Calcium (Ca)
Compound substances
- Water (H2OR)
- Carbon dioxide (CO2)
- Sulfur dioxide (SO2)
- Sulfuric acid (H2SW4)
- Zinc oxide (ZnO)
- Iron (III) oxide (Fe2OR3)
- Sodium oxide (Na2OR)
- Calcium sulfide (CaS)
- Ethanol (CH3CH2OH)
- Carbon monoxide (CO)