Atoms are composed of electrons (negatively charged and orbiting a nucleus), neutrons, and protons. Through a force known as a chemical bond, atoms stay together.
This bond or union can develop in different ways. In the case of ionic bonding, it occurs when electrons are transferred from one atom to another. In covalent bonding, on the other hand, electrons are not transferred, but rather shared. Chemical bonds are linked to the so-called octet rule, which states that atoms tend to fill up with eight electrons to achieve stability. Thus, to reach this number, atoms share, accept or give up electrons.
Returning to the case of ionic bonds, atoms capture or give up electrons according to the octet rule. Due to the electrostatic attraction that exists between ions of different signs (one electronegative and the other electropositive), one of the atoms receives electrons from the other. This is how a simple type chemical compound is developed, which does not involve a fusion. Ionic bonding usually binds a metal to a non-metal. The metal gives up electrons, forming stable cations. The non-metal, in turn, receives these electrons that are released from the metal, giving rise to an anion that also has a stable configuration. It should be noted that in addition to the octet rule, there are exceptions. Hydrogen, for example, hits the octet with two electrons, while aluminum hits six. Each ionic bond has a series of well-defined characteristics, such as the following: * they have bonds of considerable strength, and this largely depends on the nature of the ions; * When they are at room temperature, they are solid and their structure, from the point of view of crystallography (science that studies and solves crystalline structures, that is, the solid forms of the order and the way in which the molecules are packed, the ions and atoms ), is crystalline. It is important to note that the so-called “molten salts” or “ionic liquids” do not meet this point, but are liquids; * their melting and boiling points are high, although they can decrease if the bond has a high covalent character; * Result from the interaction between two groups: metals I and II and non-metals VI and VII; * As water has an electric dipole, which is capable of solvating ions to offset the energy of the crystal lattice, ionic bonds are soluble in water. This is not true for all compounds, and reasons include low solvation energy or covalent character;
* Already in aqueous solution they become perfect conductors of electricity, once the ions are released; * Contrary to the previous point, a solid state ionic bond is not electrically conductive, due to the low mobility of its ions in the lattice. To verify these last two characteristics of ionic unions, it is possible to carry out a small experiment with elements that are easy to obtain, although it is important to take certain precautions to avoid accidents. If we create a simple electrical circuit to supply a light bulb, with a cable cut in two and joined by a salt block, the result will be null; In the same way, if we replace the salt with water, the bomb will also start. However, if we dissolve a lot of salt in water and we submerge them from the ends of the cable, finally the circuit will work as we expect, since the ions required from the salt can move and look for the pole opposite the pile.