Lewis Dot Symbols: Represent valence electrons of atoms or ions. Main group elements: number of valence electrons equals group number; transition metals may vary.

Drawing Lewis Dot Symbols: Place one valence electron on each side of the element symbol before pairing. For ions, add or remove electrons as needed.

Ionic Bonding: Involves transfer of electrons from metals (which lose electrons) to nonmetals (which gain electrons), forming cations and anions. Ionic bonds lower the energy of the system.

Covalent Bonding: Involves sharing of valence electrons between nonmetals to achieve stable electron configurations (octet rule).

Metallic Bonding: Characterized by free-flowing valence electrons among a lattice of metal ions, leading to properties like conductivity, malleability, and luster.

Electronegativity (EN): Measures an atom's ability to attract electrons. EN increases across a period (left to right) and up a group. The difference in EN between atoms determines bond polarity.

Dipole Moment: Occurs when there is a significant difference in EN between bonded atoms, resulting in a polar bond. The dipole arrow points toward the more electronegative atom.

Bond Polarity: Determined by the difference in EN values. Zero difference = nonpolar covalent; small difference = polar covalent; large difference = ionic bond.

Octet Rule: Main group elements tend to achieve eight valence electrons through bonding. Some elements can have incomplete or expanded octets.

Formal Charge: Used to determine the most stable Lewis structure. Formal Charge=Valence Electrons−(Nonbonding Electrons+Bonds)

Bonding vs. Nonbonding Electrons: Bonding electrons are shared between atoms; nonbonding (lone pair) electrons are not shared.

Practice Problems: Include drawing Lewis dot symbols for ions, identifying types of bonding, calculating formal charges, and determining bond polarity and dipole moments.