Covalent Bonding

Covalent Bonding

• A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.
• Electron pair sharing occurs to fulfill the requirement for the octet rule, which states that atoms strive to have eight electrons in their outermost shell.
• Covalent bonds are formed between non-metal atoms.

Types of Covalent Bonds

• Single covalent bond: Formed when only one pair of electrons is shared between atoms. Ex: Hydrogen gas (H2).
• Double covalent bond: Formed when two pairs of electrons are shared between atoms. Ex: Oxygen gas (O2).
• Triple covalent bond: Formed when three electron pairs are shared between atoms. Ex: Nitrogen gas (N3).

Characteristics of Covalent Compounds

• Covalent compounds have low boiling and melting points due to the weak forces of attraction between the molecules.
• They are typically poor conductors of electricity and heat as they do not contain free electrons or ions.
• Most covalent compounds are volatile and have low polarity.

Covalent Structures

• Simple molecular structures: These consist of molecules where the atoms are joined by covalent bonds. Examples include oxygen (O2) and methane (CH4).
• Giant covalent structures: These contain a lot of non-metal atoms, each joined to adjacent atoms by covalent bonds. Examples include diamond (an allotrope of carbon) and silicon dioxide (silica).

Covalent Bond Energy

• The strength of covalent bonds differs in every molecule and influences the physical properties of the substance.
• The amount of energy required to break a covalent bond is referred to as bond dissociation energy.
• The higher the bond dissociation energy, the stronger the covalent bond.