2Bellringer Define a cation and an anion. Give one example of each. CationsAnions
3IonsRemember:Cations – positively charged atoms that have lost electronsAnions – negatively charged atoms that have gained electronsValence Electrons – electrons in the highest occupied energy level of an atomOctet Rule – all atoms want to be like noble gases and have 8 electrons
4Vocabulary Activity Valence electrons Chemical Formula Alkali Metals Electron dot structuresFormula UnitAlkaline Earth MetalsCoordination NumberOctet ruleHalogensHalide ionsMetallic BondsNoble GasesCationsAlloysTransition MetalsAnionsIonization EnergyIonic compoundsElectronegativityIonic BondsAtomic Radii
5Ionic Bond FormationIonic Bond – form between a metal cation and nonmetal anionTo follow the octet rule, the cation gives up an electron(s) to the anion, which bonds the two ions together.When the two ions bond, they become a neutrally charged compound.
7Electron Dot DiagramsElectron dot diagrams can be used to illustrate how many valence electrons an atom has.Examples:
8Fixed Charge Ionic Compounds Formula to Name Steps (MgS)The cation always comes first in the name (magnesium)The anion comes second in the name, and the suffix “-ide” is added to the stem of the anion name (sulfide)Final name: Magnesium sulfide
9Fixed Charge Ionic Compounds Name to Formula Steps (Aluminum oxide)Write down the charge and symbol of the cation (Al3+)Write down the charge and symbol of the anion (O2-)Remember that ionic compounds are neutral. Use the necessary number of cations and anions to balance the charges. (2 Al and 3 O)Final formula: Al2O3
10Polyatomic Ion Nomenclature: Formula to Name Rules Fe(NO3)2Decide if the cation shows variable change. If it does, you will have to use a Roman numeral to denote the charge. (Iron (II))Determine the name of the polyatomic ion. (Nitrate)Final name: Iron (II) nitrateCa(ClO3)2If the cation does not show variable change, you do not need a Roman numeral (calcium)Determine the name of the polyatomic ion (chlorate).Final name: Calcium chlorate
11Polyatomic Ion Nomenclature: Name to Formula Rules (copper (II) chlorate)The first word provides the symbol of the cation (Cu).The Roman numeral provides the charge of the cation (+2).The second word provides the symbol of the anion (ClO3-).Remember the charges need to balance out, so provide the correct number of ions needed to gain a neutral charge.Final name: Cu(ClO3)2
12Properties of Ionic Compounds Crystalline solids at room temperatureHigh melting points (typically above 300°C)High boiling pointsHigh hardnessSoluble in waterCan conduct an electric current when dissolved or melted
13Causes of Properties Intermolecular Forces Intramolecular Forces Attractions between ionic compoundsStrong, but can be disturbedIntramolecular ForcesAttractions within ionic compoundsVery strong in ionic compoundsHow do these forces affect the properties of ionic compounds?