Ionic Compounds SNC2DI

Terms to Know Valence –The combining capacity of an element Valence shell –The outer electron shell of an atom, the electrons in this shell are called valence electrons

Anions Cl 1- The chlorine atom now has a charge of -1 because it has gained an electron.

Cations Na 1+ The sodium atom is now an ion with a charge of +1 because it has lost an electron.

The Ionic Bond An ionic bond is when an electron from one atom is given to another atom and they are held together by strong electrostatic forces Ionic compounds are formed when ions form a compound

Formulas for Ionic Compounds 1.Write symbols with the metal first (metal+nonmetal 2.Write the combining capacity for each element over the symbol 3.Use “cross over” method and reduce numbers to lowest ratio Al S Mg S Mg S 

Naming Ionic Compounds Metal first non-metal second Change ending of non-metal to “ide” magnesium + fluorine  magnesium fluoride aluminum + sulphur  aluminum sulphide

Multivalent Ions Some metals form more than one type of ion –E.g. Fe can be Fe 2+ or Fe 3+ and we use roman numerals to tell them apart

Formulas for Multivalent Ions iron (II) + fluorine  iron (II) fluoride Fe F  FeF 2 iron (III) + fluorine  iron (III) fluoride Fe F  FeF

Homework Read Chapter 5.8 Q. 1-9 on P. 195 Created by Carl Fusco