OCTET RULE Atoms of different elements want to assume the s2p6 configuration of the noble gas. The s2p6 configuration contains 8 valence electrons hence the term octet. Metals, being less electronegative, tend to give away electrons. Non-metals, being more electronegative, tend to accept electrons. Only valence electrons participate in a chemical reaction.

Noble Gas Electron Configuration http://www.wou.edu/las/physci/ch334/lecture/lecture1.htm

Losing electrons results to the formation of electropositive ion (cation). Gaining electrons results to the formation of electronegative ion (anion)

Cations and anions are attracted to one another, resulting to the formation of ionic bonds

What is an Ionic Compound?

OCTET RULE IN ACTION Both lithium and fluorine wants to have the noble gas configurations (helium and neon, respectively).

PROPERTIES OF IONIC COMPOUNDS HIGH MELTING POINT – Well above room temperature with some reaching above 1000 oC; Indicates strong attractive force between the molecules Fe2O3 NaCl

HARDNESS AND MALLEABILITY– ALL ionic compounds are hard and brittle at room temperature

ELECTRICAL CONDUCTIVITY – non-conductors as solid but conductors as liquid

The valence electrons in the s and p subshells of the representative elements are represented by dots.

LEWIS DOT STRUCTURE or ELECTRON DOT NOTATION The valence electrons are written as dots placed around the symbol of the element. Na O Mg

IONIC BONDING USING ELECTRON DOT NOTATION K + Cl - + K Cl K + Cl  KCl

Mg + Br + Br 2+ - - Br Br Mg Mg + Br2  MgBr2