Monday, November 9, 2015 Bell Ringer: Define electronegativity. a measure of the ability of an atom in a chemical compound to attract electrons. On the periodic table, where are the LEAST/MOST electronegative elements found? Least-Bottom left Most-Top right EQ: What are the rules for writing and naming stable ionic formulas?

Chemical Bonding Vocabulary (Ch. 7 & 8) Word Definition My Own Words Pic. Or Ex. Chemical formula Covalent bond Ionic bonds Ionic compounds Diatomic molecule Double covalent bond Polyatomic ion Octet rule Single covalent bond Triple covalent bond Valence electrons

CHEMICAL BONDING To play the movies and simulations included, view the presentation in Slide Show Mode.

Chemical Compounds Atoms of elements are not chemically stable until they have 8 valence electrons (octet rule). Atoms gain, lose, or share electrons with other atoms to become chemically stable (8 valence electrons) The action taken by the electrons determine the type of bond formed Transferred  ionic bond (gain/lose) Shared  covalent bond

Introduction to Chemical Bonds TWO basic forms of bonding: Ionic—transfer of 1 or more electrons from one atom to another (one loses, the other gains) forming oppositely charged ions that attract one another Covalent—some valence electrons shared between atoms Most bonds are not perfectly ionic or covalent.

The type of bond can usually be calculated by finding the difference in electronegativity of the two atoms that are going together.

Electronegativity Difference If the difference in electronegativities is between: 1.7 to 4.0: Ionic 0.0 to 1.7: Covalent Example: NaCl Na = 0.9, Cl = 3.0 Difference is 2.1, so this is an ionic bond!

Is the first element a metal? Compounds Is the first element a metal? No, the first element is not a metal. Yes It’s Ionic! Is H is the positive ion? No Metals: Groups I & II, or B or Al Metals: Transition and all others Polyatomic ions Acidic Compound Covalent Compound

IONIC BONDING

Ionic Compounds Ionic bonds form from the attractions between oppositely charged ions. Metal + Nonmetal Metals tend to lose electrons to become positively charged (cations) Nonmetals tend to gain electrons to become negatively charged (anions)

QR Code Activity-Example F K Dot Diagrams (show valence electrons)

QR Code Activity-Example + _ K F The ionic bond is the attraction between the positive K+ ion and the negative F- ion

QR Code Activity-Example KF Put the symbols together and you have the chemical formula

Naming Ionic Compounds KF For the first element, use the full element name Potassium For the second element, change the ending to “-ide” Fluoride Potassium Fluoride

Label your Periodic Table:

Determine the chemical formulas by balancing the charges. Bonding pair Cation Anion Balance Charges Formula Name Sodium and Chlorine Calcium and Fluorine Aluminum and Oxygen

Special Ions Transition Metals Can have more than one charge Ex: Cu+ and Cu2+ Ex: Fe2+ and Fe3+ Use a Roman Numeral in the name to show the charge copper(I) and copper(II) iron(II) and iron(III)

Transition metals Use a roman numeral to indicate the charge of the metal for all metals other than Groups 1 & 2 and Aluminum. Example: Copper & Oxygen Cu +1 O Cu +2 Cu +3

QR Codes!

1. What is the name for NaCl? A. sodium chloride B. sodium chlorine C. sodium I chloride

2. What is the correct formula for iron (III) chloride? A. FeCl B. Fe3Cl C. FeCl3

3. What is the correct formula for Al+3 and Cl-1? A. Cl3Al B. AlCl C. AlCl3

4. What is the name for CaF2? A. calcium fluoride B. calcium II fluorine C. calcium II fluoride

5. What is the correct formula for compound formed when a sodium ion combines with a fluoride ion? A. NaF2 B. NaF C. Na2F

6. What is the correct formula for copper (II) chloride? A. CuCl B. Cu2Cl C. CuCl2

7. What is the correct formula for calcium oxide ? A. CaO2 B. CaO C. Ca2O

8. What is the name for MgS? A. magnesium II sulfide B. magnesium sulfur C. magnesium sulfide

9. What is the correct formula for silver (I) chloride? A. SiCl B. AgCl C. AgCl3

10. What is the formula formed by a potassium ion and a sulfur ion? A. K2S B. KS C. KS2

11. What is the compound formed from Ca +2 and F-1? A. calcium fluoride B. calcium II fluorine C. calcium II fluoride

12. What is the formula formed by Li +1 and O-2? A. Li2O B. LiO C. LiO2

Monday, November 9, 2015 Bell Ringer: Define electronegativity. a measure of the ability of an atom in a chemical compound to attract electrons. On the periodic table, where are the LEAST/MOST electronegative elements found? Least-Bottom left Most-Top right EQ: What are the rules for writing and naming stable ionic formulas? The positive and negative charges must be balanced. Change the ending of the nonmetal’s name to “-ide”.