Bonding: Ionic, Metallic, & Covalent Chemical Bonding-Focus Ionic! Vocabulary Chemical Bond attractive force between atoms or ions that binds them together as a unit The type of bond is determined by how the valence electrons are shared among the bonded atoms The energy required to break a bond = “Bond Energy” Vocabulary Ionic Bond Formed when valence electrons are completely transferred from one atom to another. Not a “real” bond, is an electrostatic attraction of ions!! Attraction between anions and cations Occurs between metals and nonmetals – large difference in electronegativity. Valence Electrons: ELECTRONS AVAILABLE FOR BONDING The Formation of Sodium Chloride Sodium has 1 valence electron Chlorine has 7 valence electrons An electron transferred gives each an octet Na: 1s22s22p63s1 Cl: 1s22s22p63s23p5 The Formation of Sodium Chloride This transfer forms ions, each with an octet: Na+ 1s22s22p6 Cl- 1s22s22p63s23p6 Properties of Ionic Compounds IONIC Bond Formation Type of Structure Physical State e- are transferred from metal to nonmetal crystal lattice solid Melting Point high Solubility in Water yes Electrical Conductivity yes (solution or liquid) Other Properties Ionic Bonding - Crystal Lattice All salts are ionic compounds and form crystals RETURN Dot Notations – Period 2 Lewis dot notations for the valence electrons of the elements of Period 2. lithium beryllium boron carbon Li Be B C nitrogen oxygen fluorine neon N O F Ne Lewis Structures Electron Dot Diagrams X show valence e- as dots distribute dots like arrows in an orbital diagram 4 sides = 1 s-orbital, 3 p-orbitals EX: oxygen 2s 2p O Lewis Structures Octet Rule Most atoms form bonds in order to obtain 8 valence eFull energy level stability ~ Noble Gases Ne Lewis Structures & Bonding Ionic – show transfer of e- Ionic Boding! RETURN Lewis Structures & Bonding Examples: Al & Br K&O Lewis Structures & Bonding Mg & N