The electrostatic attraction between oppositely charged ions in a chemical compound forms an ionic bond, also known as an electrovalent bond. When the valence electrons of one atom are permanently transferred to another atom, this bond is formed. The atom that loses electrons becomes a positively charged ion, while the atom that absorbs electrons becomes a negatively charged ion. Here we will discuss in detail that what is ionic bond and what are its properties?
Ionic bonding is the predominant interaction found in ionic compounds and it involves the electrostatic attraction between oppositely charged ions with different electro negativities. Along with covalent and metallic bonding, it is one of the most common forms of bonding. The full movement of one or more electrons from one atom to the other forms a chemical bond between two atoms, causing the atoms to attain their nearest inert gas configuration.
There are three main ways for two atoms to merge in order to lose energy and become stable. One way is to complete their octet configuration by donating or accepting electrons. An ionic bond is formed by this type of combination. When one atom gains electrons while the other loses electrons from its outermost level or orbit, this bond is formed. Ions with opposite charges can form an ionic bond in such a way that the compound’s total charge is zero. The octet rule states that Na forms Na+ ions and Cl forms Cl– ions to form a stable octet. As the opposite charges cancel each other out, the compound produced will be NaCl, which is neutral.
Ionic bond and covalent bond
A polar covalent bond is an extreme case of an ionic bond, with the latter arising from unequal electron sharing rather than total electron transfer. Ionic bonds are formed between the atoms having different electro negativities, while covalent bonds are formed when the electro negativities are identical.
How Ionic bond is formed?
Ionic bonding may occur as a result of a redox reaction in which atoms of a low ionization energy element (usually metals) give up some of their electrons to obtain a stable electron configuration. Cations are produced as a result of this process. An atom of a different element (usually nonmetal) with a higher electron affinity accepts one or more electrons in order to achieve a stable electron configuration and the atom becomes an anion after accepting electrons. For elements in the s-block and p-block, the stable electron configuration is usually one of the noble gases, with specific stable electron configurations for d-block and f-block elements.
Sodium chloride, for example, is a popular table salt. When sodium (Na) and chlorine (Cl) are mixed, the sodium atoms lose an electron and form cations (Na+), while the chlorine atoms gain an electron and form anions (Cl–) as the electronegativity of chlorine is greater than that of sodium. These ions are then attracted to each other in a 1:1 ratio to form sodium chloride (NaCl).
Properties of ionic bond and Ionic Compounds
- Ionic compounds are formed when atoms form ionic bonds with one another.
- Ionic compounds are strong electrolytes.
- Ionic bond is the strongest form of chemical bond.
- The ionic bond is the most reactive of all the bonds in the proper medium because it has charge separation.
- The bond has a partial positive charge on one atom and a partial negative charge on the other. Because of the electronegativity difference, the bond becomes polar and certain compounds are polar.
- Ionic compounds have high melting and boiling points. To overcome the attraction between the positive and negative ions in ionic compounds, high temperatures are needed.
- Ionic compounds have high enthalpies of fusion and vaporization, due to the strength of the ionic bond.
- Polar compounds are often soluble in water.
- The melting and boiling points of ionic bonded molecules are extremely strong.
- Ionic bound molecules are strong conductors of electricity in their aqueous solutions or molten state. This is because of ions which serve as charge carriers.
- They are found in form of crystals.
- Ionic crystals are difficult to distinguish since positive and negative ions are strongly attracted to one another. When pressure is applied to an ionic crystal, ions of similar charge can be brought closer together.
- Ionic solids are brittle because electrostatic repulsion is strong enough to break the crystal.
- When dissolved in water, they conduct electricity.
- Ionic solids do not conduct electricity well, except when molten or in aqueous solution, since the ions are so closely bound to each other.
Examples of ionic bond
Sodium chloride (NaCl), sodium bromide, sodium fluoride, sodium iodide, potassium fluoride, potassium chloride, potassium iodide, potassium bromide, lithium iodide, lithium oxide, magnesium oxide, magnesium sulfide, magnesium selenide, calcium chloride, Calcium oxide and Calcium selenide are common examples of ionic compounds.