Chemical bonding is the force of attraction that holds atoms together in molecules and compounds. This force arises from the interaction of electrons between atoms. There are primarily two main types of chemical bonds: ionic and covalent.
Ionic Bonding
- Formation: Occurs between a metal and a non-metal.
- Process: The metal atom loses an electron (forming a cation), while the non-metal gains an electron (forming an anion). The oppositely charged ions are attracted to each other, forming an ionic bond.
- Example: Sodium chloride (NaCl)
Covalent Bonding
- Formation: Occurs between two non-metals.
- Process: Atoms share electrons to achieve a stable electron configuration.
- Types:
- Single covalent bond: One pair of electrons is shared.
- Double covalent bond: Two pairs of electrons are shared.
- Triple covalent bond: Three pairs of electrons are shared.
- Example: Hydrogen molecule (H₂)
Polar and Nonpolar Covalent Bonds
- Polar covalent bond: The electrons are shared unequally between the atoms due to differences in electronegativity.
- Nonpolar covalent bond: The electrons are shared equally between the atoms.
Intermolecular Forces
These are forces of attraction between molecules, which are generally weaker than chemical bonds. They include:
- London dispersion forces: Temporary attractive forces between molecules due to the instantaneous dipole moments.
- Dipole-dipole forces: Attractive forces between polar molecules.
- Hydrogen bonding: A special type of dipole-dipole force involving hydrogen bonded to highly electronegative atoms (oxygen, nitrogen, or fluorine).
Key Concepts to Remember:
- The octet rule: Atoms tend to gain, lose, or share electrons to achieve a stable configuration with eight valence electrons.
- Electronegativity: The ability of an atom to attract electrons towards itself in a covalent bond.
- Lewis structures: Diagrams that show the arrangement of atoms and electrons in a molecule.
By understanding these fundamental concepts, you can better grasp the nature of chemical bonding and its implications in various chemical phenomena.
