Covalent Bonding

Covalent Bonding Basics

  • Covalent bonding is the process where atoms share pairs of electrons to achieve a full outer shell, leading to stable molecules.
  • Non-metal elements are the primary types to form covalent bonds.
  • Covalently bonded substances have low melting and boiling points because of the weak intermolecular forces among the molecules.
  • They are also usually poor electrical conductors as they do not have free electrons or ions.
  • In solid state, covalent compounds might form simple molecules or giant covalent structures.

The Bonding and its Classification

  • The shared pair of electrons form the basis of the covalent bond.
  • Single, double and triple covalent bonds can be formed by sharing one, two and three pairs of electrons respectively.
  • A dative covalent bond or coordinate bond is a kind of covalent bond where one atom supplies both electrons of the shared pair.
  • Covalent bonds can be broken in two ways: homolytic fission where each atom takes one electron of the pair and heterolytic fission where one atom takes both electrons of pair leading to ions.

Priority of Covalent Bonding

  • Electronegativity determines the extent to which an atom can attract a bonding pair of electrons towards itself.
  • Polarity in covalent bonding occurs when electrons are shared unequally due to difference in electronegativity, creating partial positive and negative ends.

Shapes of Molecules

  • The shapes of molecules or ion can be predicted using Valence Shell Electron Pair Repulsion (VSEPR) theory.
  • It states that electron pairs repel each other and arrange themselves in a way that minimises these repulsions, this determines the shape of the molecule.

Keywords to Remember

  • Intermolecular forces: The forces of attraction between molecules.
  • Polarity: The unequal distribution of electron density in a molecule, leading to partial charges.
  • VSEPR theory: A theory for predicting the shapes of molecules based on electron-pair repulsion.

Master covalent bonding, and you will be well equipped to understand many reactions and behaviours in organic and inorganic chemistry. If you encounter difficulties, seek assistance from your tutor or peers.