What is an Ionic Bond?
The electrostatic force of attraction which holds the two oppositely charged ions together is called the ionic bond.
A chemical bond is formed between two atoms by the complete transfer of one or more electrons from one atom to the other as a result of which the atoms attain their nearest inert gas configuration.
There are primarily three ways in which two atoms combine together to lose energy and to become stable. One of the ways is by donating or accepting electrons so as to complete their octet configuration. The bond formed by this kind of combination is known as an ionic bond or electrovalent bond. This kind of bond is formed when one atom gains electrons while the other atom loses electrons from its outermost level or orbit.
Electronegativity and Ionic Bonding
- An Ionic bond is the bond formed by the complete transfer of valence electron so as to attain stability.
- This type of bonding leads to the formation of two oppositely charged ions – positive ion known as cations and negative ions are known as anions.
- The presence of two oppositely charged ions results in a strong attractive force between them. This force is an ionic or electrovalent bond.
- Ionic bonds form between atoms with large differences in electronegativity, whereas covalent bonds formed between atoms with smaller differences in electronegativity.
- The compound formed by the electrostatic attraction of positive and negative ions is called an ionic compound.
Ionic Bond Vs Covalent Bond
|Ionic Bond||Covalent Bond|
|The ionic bond is the attraction between positive and negative ions in a crystal and compounds held together by ionic bonds are called ionic compounds.||The covalent bond is a bond formed when two atoms share one or more electron pairs. Each atom contributes an equal number of electrons towards the bond formation.|
|If the difference of ionization potential between the two atoms is more ionic compounds are formed.||Atoms with higher ionization potential are unable to lose their valence electrons and hence prefer to form covalent bonds by sharing of electrons.|
|Atoms with greater electronegativity difference lead to the formation of an ionic bond.||If the electronegativities of the combining atoms do not differ much then the bond formed between them is likely to be covalent.|
|Example: NaCl||Example: HCl|
Ionic Bond Properties
Due to the presence of a strong force of attraction between cations and anions in ionic bonded molecules, the following properties are observed:
- The ionic bonds are the strongest of all the bonds.
- The ionic bond has charge separation and so they are the most reactive of all the bonds in the proper medium.
- The ionic bonded molecules have high melting and boiling point.
- The ionic bonded molecules in their aqueous solutions or in the molten state are good conductors of electricity. This is due to the presence of ions which acts as charge carriers.
Examples of Ionic Bonds
The following table shows the elements and the ions formed by them when they lose or gain e‑.
|Element||Electronic config.||Reaction||Formed ion|
|Na(11)||2,8,1||Na → Na+ + e– ………………….. Reaction 1||Na+|
|Ca(20)||2,8,8,2||Ca → Ca2+ + 2e–……………….. Reaction 2||Ca2+|
|Cl(17)||2,8,7||Cl + e–→ Cl– ………………….……. Reaction 3||Cl–|
|O(8)||2,6||O + 2e–→ O2-…………………… Reaction 4||O2-|
- Now when Na reacts with Cl, reaction 1 and reaction 3 will take place and the resultant compound will be NaCl.
- When Na reacts with O, reaction 1 and reaction 4 will take place and the resultant compound will be Na2
- When Ca reacts with Cl, reaction 2 and reaction 3 will take place and the resultant compound will be CaCl2.
- When Ca reacts with O, reaction 2 and reaction 4 will take place and the resultant compound will be CaO.
1. What makes an ionic bond?
Ans: Ionic bond, also known as an electrovalent bond, type of connection created in a chemical compound from the electrostatic attraction of oppositely charged ions.
2. How do you identify an ionic bond?
Ans: There is an ionic bond between the metal and non-metal and a covalent bond between two non-metals. So you usually just look at the periodic table and determine if your compound is made of a metal/nonmetal or only 2 nonmetals.
3. Which is stronger bond ionic or covalent?
Ans: Covalent is stronger because the two atoms contain two or more electrons of the exterior shell. When a valence exterior shell electron is moved from one atom to another, ionic bonds are created-a much weaker interaction.
4. Why ionic bonds are not real bonds?
Ans: Ionic bonds are formed by the complete transfer of electron(s) forming a cation and anion from one atom to another. This produces a powerful electrostatic attraction force between the ions. It is not regarded as a true bond because of the creation of electrostatic attraction alone.
5. Is ionic bond polar?
Ans: A totally polar bond is called an ionic bond more properly, and happens when the distinction between electronegativities is sufficiently big that one atom effectively takes one electron from the other.
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