Presentation on theme: "+ Chapter 7 Ionic Bonding. + Bellringer Define a cation and an anion. Give one example of each. Cations Anions."— Presentation transcript:
+ Chapter 7 Ionic Bonding
+ Bellringer Define a cation and an anion. Give one example of each. Cations Anions
+ Ions Remember: Cations – positively charged atoms that have lost electrons Anions – negatively charged atoms that have gained electrons Valence Electrons – electrons in the highest occupied energy level of an atom Octet Rule – all atoms want to be like noble gases and have 8 electrons
+ Vocabulary Activity Valence electrons Electron dot structures Octet rule Halide ions Cations Anions Ionic compounds Ionic Bonds Chemical Formula Formula Unit Coordination Number Metallic Bonds Alloys Ionization Energy Electronegativity Atomic Radii Alkali Metals Alkaline Earth Metals Halogens Noble Gases Transition Metals
+ Ionic Bond Formation Ionic Bond – form between a metal cation and nonmetal anion To 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.
+ Electron Dot Diagrams Electron dot diagrams can be used to illustrate how many valence electrons an atom has. Examples:
+ Fixed 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
+ Fixed Charge Ionic Compounds Name to Formula Steps (Aluminum oxide) Write down the charge and symbol of the cation (Al 3+ ) Write down the charge and symbol of the anion (O 2- ) 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: Al 2 O 3
+ Polyatomic Ion Nomenclature: Formula to Name Rules Fe(NO 3 ) 2 Decide 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) nitrate Ca(ClO 3 ) 2 If 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
+ Polyatomic 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 (ClO 3 - ). Remember the charges need to balance out, so provide the correct number of ions needed to gain a neutral charge. Final name: Cu(ClO 3 ) 2
+ Properties of Ionic Compounds Crystalline solids at room temperature High melting points (typically above 300°C) High boiling points High hardness Soluble in water Can conduct an electric current when dissolved or melted
+ Causes of Properties Intermolecular Forces Attractions between ionic compounds Strong, but can be disturbed Intramolecular Forces Attractions within ionic compounds Very strong in ionic compounds How do these forces affect the properties of ionic compounds?