There are different kinds of chemical bonds. Among them are covalent, metallic, van der Waals, hydrogen and ionic. Let's find out what an ionic bond is and what its properties are.
A chemical bond, carried out by the transition of a common pair of electrons from one atom, less electronegative, to another, more electronegative, is what an ionic bond is. Examples of compounds formed by it can be combined by a common feature - the content of atoms with strong electronegativity and metal atoms in the compound.
A metal atom easily gives up an electron and becomes a cation. And an electronegative atom, such as a halogen atom, easily accepts an electron, forming a negatively charged ion. These charged particles - anions and cations - form one that has the name "ionic bond". Examples of it are sodium chloride, potassium bromide, lithium iodide and other metal halides (mainly alkaline).
But a compound cannot be formed by an ionic bond alone. The reason for this is the uncompensated forces of attraction and repulsion. Therefore, it is worth talking only about the predominantionic bond, while along with it there is another chemical bond. This is extremely important to know.
Does not have the properties of directionality and saturation of the ionic bond. Examples of bonds with directionality and saturation are covalent, donor-acceptor bonds. The unsaturation and non-directionality of the ionic is manifested because when ions with a different charge are attached, the charge is not completely compensated. Other oppositely charged ions can be attached, and so on. that is why around the ion is the maximum possible number of similar to it, but with a different sign. However, this number is limited due to the mutual repulsion of ions of the same charge. Equilibrium is achieved with their certain mutual arrangement, which is characterized by a coordination number. This indicator depends on the ratio of ion radii. Substances with an ionic bond often have the coordination of a cube or an octahedron and are crystals.
So, a crystal of table s alt - sodium chloride - has a cubic lattice. In it, each chloride ion is associated with six sodium ions and each sodium ion is associated with six chloride ions.
In oxides of alkali and alkaline earth metals, ionic bonding is also observed. Examples of such compounds: calcium oxide, sodium oxide and others. Ions can consist not only of one atom, but of several. Inside such a complex ion is different, and between the ions themselves there is an ionic bond. Examples: s alts like potassium sulfate (here potassium is a cation, sulfate ion is an anion).
It should also be noted that the properties of ionssubstances differ greatly from the properties of atoms and molecules of these substances. So, for example, chlorine ions, which are part of sodium chloride, are colorless and odorless and suitable for food, while molecular chlorine, a greenish-yellow gas with a pungent odor, is a poison. And sodium atoms with water react with an explosion, while ions dissolve freely.
