In Chemistry different compounds are formed by different types of bonds between the molecules. Various factors determine what type of bond should be formed between different molecules and the type of molecules plays a huge role in the formation of such bonds. A bond is an attractive force acting between two molecules.
Ionic Bonds vs Covalent Bond
The main difference between Ionic Bonds and Covalent Bonds is that Ionic bonds are formed between molecules that contain charged ions, whereas covalent bonds are formed between molecules by a mutual sharing of electrons. An ionic bond is formed due to electrical attraction between two molecules, whereas a covalent bond is formed due to the presence of electrons.
An ionic bond is formed in the case of ionic compounds. Ionic compounds are made of molecules that contain charged ions, which could either be positively charged or negatively charged. Thus this creates a force of attraction between the molecules as opposite charges attract each other. This force of attraction results in the formation of the bond.
Covalent bonds are usually formed between non-metals. This type of bond is formed due to sharing of electrons between two molecules. As one of the molecules in a covalent compound is electron deficient, it receives the required number of electrons from the donor molecules to create the stable covalent compound.
Comparison Table Between Ionic and Covalent Bond
| Parameters of Comparison | Ionic Bond | Covalent Bond |
| Creation | Ionic bonds are formed due to the transfer of ions between molecules | Covalent bonds are formed due to sharing of electrons between two molecules |
| State of compound | The compounds formed are present only in solid-state | The compounds formed are present in all states of matter |
| Type of molecules | The bonding occurs between a metal and a non-metal | The bonding occurs between two non-metals |
| Polarity | Ionic compounds are nonpolar | Covalent compounds are polar |
| Melting Point | Ionic compounds have higher melting points | Covalent Compounds have lower melting points |
What is Ionic Bond?
An ionic bond is one of the three types of bonds that occur between molecules, forming an ionic compound. The bond occurs between a metal and a non-metal, and one of the most common examples of such a compound is salt (NaCl), in which Sodium (Na) is a metal and Chlorine (Cl) is a non-metal.
It is a strong bond and cannot be broken as easily, as in the case of covalent bonds. The bond occurs due to a sharing of electrons between the metal and the non-metal.
As one of the molecules in an ionic compound is electron deficient, while the other molecule is electron-rich, it creates a force of attraction between the two molecules.
The electrostatic force of attraction results in the interaction between the two molecules, resulting in the sharing of electrons from the electron-rich atom to the electron-deficient atom.
The donor atom or molecule completely transfers the atom to the receiver molecule or atom, resulting in a strong and clean bond between the two molecules.
Some of the characteristics of such ionic compounds are their high melting points and high electrical conductivity in a molten or dissolved state. Ionic compounds are also highly soluble in water.
What is Covalent Bond?
A covalent bond is a type of chemical bond between molecules that leads to the formation of a covalent compound. It is the weakest of the three types of chemical bonds and the molecules in a covalent compound can be easily separated.
Covalent bonds are formed between two non-metals and the bonding of metals of molecules depends on the number of electrons valence shell.
The bonding occurs by sharing of electron pairs and this sharing of electrons occurs for maintaining the chemical balance between the molecules or atoms. The sharing of electrons between two unstable molecules creates a stable valence shell in both molecules.
When both the atoms have reached their full valence state, the bond is formed between the two atoms or molecules. The shared pair of electrons is present between both atoms to maintain the stability of the compound.
The most common example of a covalent bond is between the two Hydrogen atoms in an H2 molecule. In an H2 molecule, the two Hydrogen atoms share two electrons leading to a covalent bond.
The key factor required for the formation of a covalent bond is the electronegativities of the molecules. Two atoms with similar electronegativities result in a covalent bond.
Main Differences Between Ionic and Covalent Bond
- Ionic bonds are formed due to transfer of ions between molecules. Covalent bonds are formed due to sharing of electrons between atoms.
- Ionic compounds are only present in solid state. Covalent compounds are present in all states of matter
- Ionic bond is formed between a metal and a non-metal. Covalent bond is formed between two non-metals.
- Ionic compounds are non-polar, whereas covalent compounds are polar
- Ionic compounds have very high melting points, whereas covalent compounds generally have low melting points.
Conclusion
In nature, chemical compounds are formed by one of the three chemical bonds, Ionic bond, Covalent bond, and Coordinate bond. Ionic bonds and Covalent bonds, as the name suggests, lead to Ionic and Covalent compounds.
Out of these two compounds, Ionic compounds are more stable, as the Ionic bond is a stronger bond than the Covalent bond. This is due to the nature of the formation of the bonds.
An ionic bond is formed between a positively charged ion and a negatively charged ion, due to the electrostatic force of attraction between the two ions. This results in a more stable compound, as well as a stronger bond.
A covalent bond on the other occurs between an electron-deficient molecule or atom, and an electron-rich molecule or atom. the compound is stabilized only after a pair of electrons is shared between the two molecules to fill the valence shell.
Thus as there is mutual sharing of electrons in a Covalent bond, it results in a weaker bond which can easily be broken.
References
- https://link.springer.com/article/10.1007/s00214-007-0282-x
- https://journals.aps.org/pr/abstract/10.1103/PhysRev.168.905