Ionic Compounds Metals Vs. NonMetals Metals • Left of steps on Periodic Table • 80 percent of elements are metals NonMetals • Right of steps • 20 percent – Pie chart on page 36 • Properties – – – – Luster Conductivity Malleable Ductile • Properties – May lack luster – Do not conduct • Except carbon – Brittle Electron Configuration • The properties of metals and nonmetals are greatly influenced by the electron configurations of atoms. Ionic Compounds • Atoms may gain or lose electrons thereby becoming ions. – Cation – Anion Positive Charge Negative Charge • Why might a certain Ion gain rather than lose electrons? Electron Configuration • Number of electrons in the outermost shell is key. • Few electrons Tend to lose them • Close to full Shell Tend to gain • Tendency towards stability Compounds and Ionic Bonding • A compound is a substance which is made of two or more kinds of atoms or ions which have joined together. • Attractive force between positive and negative ions creates Ionic Compounds. • NaCl Na+ Cl- • The force of attraction between the positive and negative ions is known as an Ionic bond. IMPORTANT • When we talk about stability we are referring to the number of electrons in the valence shell. Review • • • • • • Atom Ion Cation Anion Why does an atom lose or gain electrons? Predictions – Fluorine, Potassium, Lithium • How many Chloride ions bond with Magnesium ions? Forming Ionic Compounds (Salts) • Ionic bonds form between METALS and NONMETALS when Electrons are transferred (lost or received). • Columns 1,2,13 may transfer with columns 15,16,17. Forming Ionic Compounds • Electrons get transferred as a result of energy input. This may also occur when materials are placed in solution. • A variety of combinations are possible depending on the valence electron number. Atom gained one electron. It now has a negative charge. This atom lost one electron and now has a positive charge. Ionic Bonds • An ionic bond is the attraction between a positively charged cation and a negatively charged anion. Metals in columns NonMetals in 1, 2, 3 are electron columns 5, 6, 7 donors. receive Electrons. Which Elements form Ionic Bonds? • The central idea (for the 50th time) is that electrons, one or more, are transferred between the outer shells of adjacent atoms. This Creates Ions/Charged Atoms. • Metals and NonMetals. • Certain Elements may donate or receive more than one electron. It can therefore bond with multiple elements. Example #1 Na and Cl • How many valence electrons does each atom have? • Which atom will tend to Receive e-? Donate? • What is the charge on each ion? • What will the ratio between Na and Cl be? Example #1 Na and Cl • Sodium would lose one electron and become positively charged, while Chlorine would gain one electron becoming negatively charged. • The positive/negative charge attraction would hold the two ions together. Example #2 Mg and O • How many valence electrons does each atom have? • Which atom will tend to Donate e-? Receive? • What is the charge on each ion? • What will the ratio between Mg and O be? Example #2 Mg and O • The Magnesium would lose two electrons, becoming +2 charged and the Oxygen would gain the two electrons becoming -2 charged in the process. • The negative/positive charge attraction (+2/-2) (four times as much as +1/-1) would hold the two ions together. Example #3 Mg and Cl • How many valence electrons does each atom have? • Which atom will tend to gain e-? Donate? • What is the charge on each ion? • What will the ratio between Mg and Cl be? Example #3 Mg and Cl • The Magnesium would lose two electrons, becoming +2 charged and two chlorines (not one) would each gain one electron, each becoming -1 charged in the process. • The three atoms would bond to each other by the positive/negative attraction between the ions. Naming Ionic Compounds • The same as naming individual ions. • Cation, Electron Donor, or Metal in compound is said first. • Anion name is changed to …….ide and said second. Examples • • • • Sodium Chloride Magnesium Oxide Lithium Nitride Potassium Bromide Using the correct Name 1) K2S 7) SrS 2) LiBr 8) Al2O3 3) Sr3P2 9) MnO 4) BaCl2 10) ZnO 5) NaBr 11) ZnCl2 6) MgF2 12) Cu2O Notation Ionic Notation • 3 Na+1 • 1 PO4-3 Ionic Compound Formula • NaCl • CaCl2 • Na3(PO4) Formulas Rules for Writing Formulas • Metallic Donor is always written first. • Nonmetallic Receiver is written second. • Write the number of atoms required to balance the formula as subscripts after the element in compound. – NaCl – MgO – MgCl2 The Ionic Compound NaCl Writing & Naming Ionic Compounds +1 Na & -1 Br Writing & Naming Ionic Compounds +2 Ca & -1 Br Writing & Naming Ionic Compounds +1 K & -2 O Writing & Naming Ionic Compounds Li ? & N ? HW: Write the Name of the Compound 1) MgS 7) KBr 2) Ba3N2 8) FeO 3) NaI 9) SrF2 4) Li2S 10) CaO 5) Na3P 11) Al2O3 6) KCl 12) Fe2O3 HW: Write the Correct Formula 1) Magnesium Oxide 2) Lithium Bromide 3) Calcium Nitride 4) Sodium Sulfide 5) Copper (I) Sulfide 6) Copper (II) Sulfide Practice Exercise #1 1. 2. 3. 4. Which will donate, Which will receive? How many will be donated/received? Write the Ionic Notation of each. Write the formula for each of the following. – Lithium Oxide – Potassium Chloride – Sodium Nitride – Calcium Chloride – Magnesium Sulfide – Barium Nitride – Aluminum Fluoride – Aluminum Oxide – Aluminum Nitride Diagramming Ionic Compounds • Lewis Structures – Diagram valence shell. • Place valence electrons around nucleus as they would be according to the octet rule Diagramming Ionic Compounds Na Cl + Na Cl Practice Exercise #2 • Diagram the following Ionic Compounds: – Lithium Oxide – Potassium Chloride – Sodium Nitride – Calcium Chloride – Magnesium Sulfide – Barium Nitride – Aluminum Fluoride – Aluminum Oxide – Aluminum Nitride Transition Metals • d block elements that can form more than one kind of ion. • Lose electrons • Why can they lose different numbers of electrons? • Copper – Cu I or Cu II • Iron – Fe II or Fe III Implications • Copper and Iron as well as other transition metals can form multiple ionic compounds. Polyatomic Ions • Compound Ions • A group of COVALENTLY bonded atoms that have a net charge (anion or cation) • Most, but not all are Anions. Polyatomics • • • • • • • • SO4-2 SO3-2 NO3-1 NO2-1 CO3-2 CN-1 OH-1 NH4+1 Sulfate Sulfite Nitrate Nitrite Carbonate Cyanide Hydroxide Ammonium Na3PO4 Na P O PO4-3 O O P O Phosphate can accept 3 electrons. O When it does it has a negative 3 charge. It is therefore called a……….. Sodium Phosphate O Na O P O Na Na3PO4 O Na Practice Exercise #3 Give the Ionic Notation and Formula for each. – Potassium Sulfate – Magnesium Sulfite – Aluminum Nitrate – Sodium Nitrite – Lithium Carbonate – Sodium Cyanide – Barium Hydroxide – Ammonium Chloride – Ammonium Hydroxide Draw/Diagram Magnesium Sulfite Practice Exercise #4 • Write out the Ionic Notation, Formula and Names of the following ionic compounds: – Li and F – Na and S – K and Br – Rb and O – Ca and Cl – Mg and SO3-2 – Al and NO3-1 - Na and CO3-2 - Li and OH-1 - NH4+1 and Cl - Ca and SO4-2 - NH4+1 and OH-1 - Na and CN-1 - NH4+1 and SO4-2