The rock mass that makes up the Earth is composed of different substances that combine with each other. The chemical is the discipline that studies these substances and for this reason spoken of the chemical elements.
Most materials found in nature are mixtures of substances. For example, in a drop of water there is a combination of hydrogen atoms and another of oxygen or common salt formed by atoms of sodium and chlorine.
Certain elements are not found naturally on Earth, but are synthesized by humans as is the case with the neptune.
Living things are also the product of a mixture of chemical elements. On the other hand, in a granite stone it is also possible to find other combinations of chemical substances such as quartz, mica, among other elements.
The proportions of materials that make up a mixture can vary. This is because the particles that make up the mixture are irregularly disposed.
Not all particles in the mixtures are visible, for example oxygen. Despite its invisibility, oxygen is essential for living beings. We must not forget that oxygen is important in living beings to transform food into energy .
Currently, more than one hundred chemical elements are known and each one of them has different characteristics and properties.
The periodic table of chemical elements
The set of chemical elements is represented by the well-known periodic table, which has a certain order through the atomic number of each element (the atomic number brings identity to the atom). The chemical elements are distributed in rows and columns: the rows correspond to the periods or energy levels of the electron configuration of each element and the columns are related to the amount of electrons in energy level.
The different types
There are four groups of chemical elements: metals, nonmetals, metalloids and noble gases. Most of the elements are metals and are characterized by being electricity conductors , by their corrosion and by melting at high temperatures (iron, cobalt, tin and copper are some examples). Non-metals combine with metals to form salts, some are brittle and others soft, while their density is lower than metals (hydrogen, carbon, nitrogen and oxygen are the most significant).
Metalloids are not metals as well as non-metals, but their properties are intermediate between one group and another. They are good semiconductors and show boron, silicon, polonium and arsenic as some of the elements in this group. Finally, noble gases are odorless and colorless elements and are called noble because they do not react with other chemical elements, as happens with helium , radium and krypton.