Chemical Bonding-Focus Ionic! Bonding: Ionic, Metallic, & Covalent

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 Cl: 1s 2 2s 2 2p 6 3s 2 3p 5 Na: 1s 2 2s 2 2p 6 3s 1  Chlorine has 7 valence electrons  An electron transferred gives each an octet

The Formation of Sodium Chloride Cl - 1s 2 2s 2 2p 6 3s 2 3p 6 Na + 1s 2 2s 2 2p 6 This transfer forms ions, each with an octet:

IONIC Bond Formation Type of Structure Solubility in Water Electrical Conductivity Other Properties e - are transferred from metal to nonmetal high yes (solution or liquid) yes Melting Point crystal lattice Properties of Ionic Compounds Physical State solid

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 Liberyllium Beboron Bcarbon C nitrogen Noxygen Ofluorine Fneon Ne

Lewis Structures Electron Dot Diagrams show valence e - as dots distribute dots like arrows in an orbital diagram 4 sides = 1 s-orbital, 3 p-orbitals EX: oxygen 2s2p O X

Lewis Structures Octet Rule Most atoms form bonds in order to obtain 8 valence e - Full energy level stability ~ Noble Gases Ne

Lewis Structures & Bonding Ionic – show transfer of e -

RETURN Ionic Boding!

Lewis Structures & Bonding Examples: Al & Br K & O

Lewis Structures & Bonding Mg & N