Chemical Bonding Overview

Chemical Bonding

• Atoms interact to achieve a completed outer electron shell, resembling the nearest noble gas.
• Two main types of chemical bonds are formed:
  • Ionic bonds: Electrons are transferred between atoms, creating charged particles (ions). This transfer forms an ionic bond.
  • Covalent bonds: Electrons are shared between atoms to complete their valence shells. Atoms share electrons to complete their valence shells.

Ionic Bond

• Electrons are completely transferred from one atom to another, forming charged ions.
• This type of bond is formed by the transfer of electrons.
• A chemical bond formed by electron transfer is called an ionic bond.
• Examples include Sodium and Chlorine.
• Sodium loses one electron, while Chlorine gains one. The electron transfer changes them to ions, creating an ionic bond.

Covalent Bond

• Atoms share electrons to complete their valence shells.
• A chemical bond formed by electron sharing is called a covalent bond.
• A covalent bond can be either polar or nonpolar, depending on electronegativity differences of the atoms. Larger differences lead to more polar bonds.
• Examples include Cl₂ where two chlorine atoms share electrons to form a covalent bond.

Coordinate bond

• A special type of covalent bond where one atom provides both electrons shared in the bond.
• In coordinate bonds, one atom donates both shared electrons.

Hybridization

• When atomic orbitals combine to form a new set of orbitals, it's called hybridization. These new orbitals are called hybrid orbitals.
• Atomic orbitals can be hybridized to explain bond angles observed in molecules. These bond angles don't match predicted angles based on non-hybridized atomic orbitals - so hybridization explains the differences.
• Several types of hybridization exist, including sp³, sp², and sp.

Types of Hybrid Orbitals

• sp³: Formed from one s orbital and three p orbitals.
• sp²: Formed from one s orbital and two p orbitals.
• sp: Formed from one s orbital and one p orbital.

Formation of Chemical Bonds

• Overlapping hybrid orbitals can form different types of bonds depending on the overlap geometry.
  • Direct overlap forms sigma bonds.
  • Parallel overlap forms pi bonds.

sp³ Hybridization

• Example: The formation of Methane (CH₄) Carbon (C) uses sp³ hybrid orbitals when bonding with four hydrogen (H) atoms.
• Carbon's sp³ orbital configuration creates a tetrahedral shape, with 109.5° bond angles.

sp² Hybridization

• Example: Forming Ethene (C₂H₄) or Ethylene, carbon atoms use sp² hybrid orbitals.
• The hybridization of sp² creates 120° bond angles resulting in a planar shape.

sp Hybridization

• Example: The formation of Ethyne (C₂H₂). Carbon atoms use sp hybrid orbitals
• The sp hybridization creates a linear shape with a bond angle of 180°.