Covalent bond, ionic bond and diatomic molecules with examples
Covalent Bond
A covalent bond is a type of chemical bond that forms when two atoms share electrons in order to achieve a stable electron configuration. In a covalent bond, electrons are shared between the atoms rather than transferred from one atom to another.
Example of a Covalent Bond: Let's take the formation of a water molecule (H2O) as an example. In a water molecule, two hydrogen atoms (H) and one oxygen atom (O) share electrons to form covalent bonds. Each hydrogen atom shares one of its electrons with the oxygen atom, and the oxygen atom shares one of its electrons with each hydrogen atom. This sharing of electrons allows both hydrogen and oxygen to achieve a stable electron configuration:
- Hydrogen (H): 1 electron in its outer shell.
- Oxygen (O): 6 electrons in its outer shell.
After the covalent bonding, each hydrogen atom shares its electron with oxygen, resulting in both hydrogen and oxygen having a stable outer shell configuration:
- Hydrogen (H): Now has 2 electrons in its outer shell (like helium, a noble gas).
- Oxygen (O): Now has 8 electrons in its outer shell (like neon, a noble gas).
This sharing of electrons in the covalent bond leads to the formation of a water molecule with the chemical formula H2O.
Ionic Bond
An ionic bond is a type of chemical bond that forms between two atoms when one atom donates electrons (becomes a cation) while the other atom accepts those electrons (becomes an anion). This transfer of electrons results in the formation of oppositely charged ions, which are held together by electrostatic attraction.
Example of an Ionic Bond: Consider the formation of table salt, sodium chloride (NaCl). Sodium (Na) has one valence electron, which it donates to chlorine (Cl), which has seven valence electrons. Sodium loses an electron and becomes a positively charged ion (Na+), while chlorine gains an electron and becomes a negatively charged ion (Cl-). The electrostatic attraction between the oppositely charged ions, Na+ and Cl-, forms an ionic bond, resulting in the compound NaCl.
Diatomic Molecules
A diatomic molecule consists of two atoms of the same element bonded together. These molecules are formed when two atoms of the same element share electrons to achieve a stable electron configuration.
Examples of Diatomic Molecules:
- Oxygen (O2): Oxygen gas consists of two oxygen atoms bonded together by a covalent bond. Each oxygen atom shares two electrons with the other, forming a double bond.
- Nitrogen (N2): Nitrogen gas is composed of two nitrogen atoms bonded by a triple covalent bond. Each nitrogen atom shares three electrons with the other.
- Hydrogen (H2): Hydrogen gas consists of two hydrogen atoms bonded together by a single covalent bond. Each hydrogen atom shares one electron with the other.
In each of these diatomic molecules, the atoms share electrons to fill their outer electron shells, achieving a stable electron configuration.