Introduction to Chapter 5 Naming Compounds9/23/09

Two Types of CompoundsType 1 Molecular compoundsMade by joining nonmetal atoms together into molecules.Type 2 Ionic compoundsMade by combining two ions.Cation and an anion. +/-Metals and Nonmetals

Two Types of CompoundsIonic Compounds (cont.)The electrons lost by the cation are gained by the anionThe cation and anions surround each otherSmallest piece is a FORMULA UNIT

Ionic Compounds (cont.)

Chemical FormulasShows the kind and number of atoms in the smallest piece of a substanceMolecular formula- number and kinds of atoms in a moleculeCO2C6H12O6

Formula UnitThe smallest whole number ratio of atoms in an ionic compoundIons surround each other so you can’t say which is hooked to which

Charges on ionsFor most of the Group A elements, the Periodic Table can tell what kind of ion they will form from their locationElements in the same group have similar propertiesIncluding the charge when they are ions

What about the others?What about the transition metalsThey can form more than one type of ionWe have to figure those out some other wayMore on this later

Naming ionsWe will use the systematic wayCation- if the charge is always the same (Group A) just write the name of the metal.Na+1SodiumCa+2CalciumAl+3AluminumLi+1 Lithium

Write Formulas for thesePotassium ionMagnesium ion Calcium ionCesium ionBarium ionHydrogen ion

Naming AnionsAnions are always the sameChange the element ending to -ideF-1 Fluorine

Naming AnionsAnions are always the sameChange the element ending to -ideF-1 Fluoride

Name theseCl-1N-3Br-1O-2I-ChlorideNitrideBromideOxideIodide

Write theseSulfide ioniodide ionphosphide ionStrontium ion