Catalyst: Complete the Chart Element Symbol Group # # Valence Electrons Ion Formed Lewis Dot Structure Barium Ba Ba2+ Phosphorous 15 Nitrogen 5 Hint: According to the octet rule, atoms lose or gain electrons, forming ions, in order to get a full outer shell with 8 electrons. If the atom loses electrons it is a positive cation and if it gains electrons it is a negative anion.

Catalyst: Answers Element Symbol Group # # Valence Electrons Ion Formed Lewis Dot Structure Barium Ba 2 Ba2+ Phosphorous P 15 5 P3- Nitrogen N N3- Hint: According to the octet rule, atoms lose or gain electrons, forming ions, in order to get a full outer shell with 8 electrons. If the atom loses electrons it is a positive cation and if it gains electrons it is a negative anion.

TODAY’S OBJECTIVE: BONDING TODAY’S OBJECTIVE: BONDING!!!! SWBAT Differentiate between IONIC &COVALENT BONDS A.K.A.: Why don’t you blow up when you eat sodium chloride since sodium is a highly reactive metal and chlorine is an extremely poisonous gas??

Agenda Catalyst/HW Check (10) HW Review (10) Part 1: Ionic Compound Formula Review: Kris-Kross Method (20) PART 2: Ionic vs. Covalent Compounds Ionic vs. Covalent Notes (20) Ionic vs. Covalent Lab (40) Ionic vs. Covalent Conductivity Demo (10) Closing (5)

Homework Answers Having equal amounts of positive and negative charge is called electroneutrality. An electrically charged group of two or more bonded atoms that functions as a single ion is a polyatomic ion. Collections of cations are never found without a similar number of anions (or sometimes electrons) nearby to effectively neutralize the charges. The names for cations come from the element from which they are formed. When an element forms two or more positive ions, the ions are distinguished by using roman numerals to indicate the charge. The name of a simple anion is formed by changing the ending of the element name to –ide. A subscript is a whole number written below and to the right of an element’s symbol, and it is used to denote the number of atoms in a formula. Any chemical compound that is composed of oppositely charged ions is called an ionic compound.

More HW Answers K+ + Br- → KBr Ba2+ + F- → BaF2 (2 F- to balance 2+ charge) Sn4+ + O2- → SnO2 (2 O2- to balance 4+) Cs2+ + Br- → CsBr2 (2 Br- to balance 2+) The rest of the problems are coming up as practice…

Writing Ionic Compound Formulas Notes

Kris Kross Method! Ca2+As3- Ca3As2

Just kris kross the positive and the negative charges Na1+Cl1- NaCl Pb4+O2- Pb2O4

Practice Problems What ionic compound is formed? Cobalt (II) and Bromine Mercury(I) and Sulfur Aluminum and Iodine Hints: Periodic table groups tell us how many valence electrons Draw Lewis structure Metals lose electrons to form positive cations Nonmetals gain electrons to form negative anions Compounds must be neutral (equal # of + and – charges)

Part 2! Ionic vs. Covalent Bonds Make a Chart in your notes that looks like this: Ionic Bonds Covalent Bonds

Ionic vs. Covalent Bonds Bond Strength = the energy needed to break the bonds between atoms in a compound.

Ionic vs. Covalent Bonds Ionic Bonds Covalent Bonds Atoms in ionic compounds are held together by ionic bonds. Atoms in covalent or molecular compounds are held together by covalent bonds. Ionic bonds are stronger (more bond strength) Covalent bonds are weaker (less bond strength)

Ionic vs. Covalent Bonds Ionic Bonds Covalent Bonds Transfer of electrons Sharing of electrons

Ionic vs. Covalent Bonds Ionic Bonds Covalent Bonds Crystal Lattice Molecules Water (H2O) molecules Lithium Chloride (LiCl) crystal lattice

Ionic vs. Covalent Bonds Ionic Bonds Covalent Bonds Metal and nonmetal Nonmetal and nonmetal

Ionic vs. Covalent Bonds Ionic Bonds Covalent Bonds Solid at room temp. Solid, Liquid or Gas at room temp.

Ionic vs. Covalent Bonds Ionic Bonds Covalent Bonds Conducts electricity when dissolved Does not conduct electricity

Investigation: Ionic vs. Covalent You will work in groups of 4. (2 groups per table) Lab WS is due at end of class Safety! Do not put any test substances near your eyes or mouth. Clean Up: Pour liquids down the sink and solids in the trash. Objective: Conduct four tests on four substances. Predict whether they are ionic or covalent. Ms. Boon will run the conductivity test.

Exit Slip What is the formula for a compound between: Ca & F? Compare at least one difference between ionic & covalent compounds? Does the compound MgBr2 share electrons or transfer them between the atoms?

3 Types of Bonding **IONIC *COVALENT METALLIC METAL + NON-METAL How are Bonds Formed? ELECTRONS are transferred between ions (1 steals, 1 gives) Electrons are shared between atoms. “Sea of Electrons” Spread all over between atoms of the same element. Type of Bond Formed Solid Crystals with repeating patterns of (+) and (-) ions Usually liquid or solid Solid metal Who’s Involved? METAL + NON-METAL NON-METAL + NON-METAL METAL AND METAL Special Properties When dissolves in H20, conducts electricity Does not conduct electricity Very good conductors of electricity on their own!

Practice- Ionic or covalent? SH6 MgCl2 KCl NH3 H3C3O2 Li2S N2 Cl2 CsBr H2O HF Na3P CaCl2 BaS H2