Intramolecular Forces are the forces that exist between the atoms of a molecule. These forces are responsible to bind the atoms of a molecule together and make the compound stable. These forces are also accountable to provide stability to a number of compounds existing in nature. For example, Calcium chloride or rock salt, Iron Oxide or rust, Sodium chloride or table salt, etc. An intramolecular force is stronger than an intermolecular force.
Types of Intramolecular Forces
1. Ionic Bond
An ionic bond is formed by the complete transfer of valence electrons between the two atoms. This transfer of electrons leads to the formation of two oppositely charged ions. The force of attraction between these differently charged ions is responsible to hold the atoms in position. The metals donate the electrons, become positively charged in nature, and are known as cations. Similarly, non-metals accept the donated electron, become negatively charged, and are known as anions.
2. Covalent Bond
A covalent bond exists due to the mutual sharing of electrons within the atoms. The tendency of an atom to complete its octet becomes the basis of establishing a covalent bond amongst the atoms. The shared pair of electrons are also known are bonding pairs or shared pairs.
1. Polar Covalent Bond
A polar covalent bond is formed when the difference in electronegativity between the atoms to be bonded together lies within the range of 0.5 and 1.9. Since the difference between the electronegativity is very small; therefore, a polar covalent bond is said to be present between the slightly different electronegative atoms.
2. Non-Polar Covalent Bond
A non-polar covalent bond is formed when the electronegativity is less than 0.5. Therefore, this type of bond can exist between the same atoms or within the atoms of very similar electronegativity.
3. Metallic Bond
The bond that exists between the positively charged metallic ions and the valence electrons is known as the metallic bond. In metals, the outermost shells of the atoms overlap with each other. This allows the electrons present in the outermost shell to move freely and randomly. The freely moving electrons are responsible to form negatively charged electron clouds. This difference in the charges contained by the ion and the electrons establishes a force of attraction that binds the two and keeps the metallic structure stable.
Examples of Intramolecular Forces
1. Table Salt
Table salt or sodium chloride is one of the best examples of intramolecular interactions. An ionic bond is accountable to bind the atoms of sodium and chlorine together to form a stable structure of sodium chloride. Sodium donates the electron and becomes positively charged. Chlorine accepts the electron and becomes negatively charged. The force of attraction between the anion (that is chlorine) and the cation (that is sodium) leads to the formation of table salt or sodium chloride.
Toothpaste consists of a chemical compound known as sodium fluoride. It makes the teeth more resistant to decay and keeps the cavity-causing bacterias away. Sodium fluoride is made up of an ionic bond that exists between sodium, which is a metal, and fluoride, which is a non-metal. Sodium loses an electron and develops a positive charge on it, while fluoride accepts the donated electron and gets negatively charged. This transfer of electrons develops a polarity difference, which further causes a force of attraction to get developed that binds the compound together.
Diamond is formed as a result of subjecting coal to high temperature and pressure over a long period of time. It is basically a huge covalent bond of carbon. Carbon has a valency of 4 electrons, which means either it can lose or gain 4 electrons to complete its octet. Instead, it tends to share the 4 electrons with the adjacent atoms. Hence, each carbon atom is covalently bonded to the neighbouring 4 other carbon atoms. This borrowing of electrons between the atoms of carbon is a perfect example of intramolecular forces existing in nature.
Lye is an alkaline solution, which is used to make soaps and other products used for cleaning purposes. The chemical name of lye is sodium hydroxide. Sodium hydroxide is formed as a result of an ionic bond that exists between a metal and a compound. The sodium ion has a +1 charge, whereas the hydroxide atom has a -1 charge. The charges being equal and opposite in nature establishes a strong bond between the two and leads to the formation of a new product with completely different characteristics.
The metal alloys get formed as a result of a metallic bond existing between the freely moving electrons of the atoms of the elements being used. The metallic bonding, which exists between the two or more distinct elements being used to form an alloy, increases the conductivity and strength of the newly formed material. Alloying is basically a process of adding selective impurities into a pure element in order to alter and enhance its characteristics.