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: Involves free-flowing valence electrons among a lattice of metal ions, giving rise to properties like conductivity, malleability, and luster.

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

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

Chemical Bond Classification:

• Nonpolar covalent: Small or zero difference in electronegativity.

• Polar covalent: Intermediate difference in electronegativity.

• Ionic: Large difference in electronegativity.

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)

Application: Practice problems involve drawing Lewis structures for atoms and ions, identifying types of bonding, calculating formal charges, and determining bond polarity and dipole moments.