Introduction Chemical Bonding – The simultaneous (“same time”) attraction of 2 nuclei for electrons. Eg. H + H  H 2 ***if attraction is strong enough, a bond forms.

Why does Bonding take place??? 1.) All elements want 8 valence electrons... to be like a Noble Gas. (Octet Rule) 2.) To become MORE STABLE by releasing energy!

Types of Bonding 3 Types: 1.) Ionic BondingIonic Bonding 2.) Covalent BondingCovalent Bonding 3.) Metallic BondingMetallic Bonding

Ionic Bonding –Transfer (not sharing) of electrons –Transfer from Metals  Nonmetals –Salts = ionic compounds

The greater the difference in Electronegativity (E.N.), the MORE ionic! Q.1: Which bond is more ionic...NaCl or KCl???

Q.2: Which bond is the most ionic... a.) KCl b.) CaCl 2 c.) MgS d.) KF Q.2: Which bond was the least ionic?

HW: Read pp Write a ½ page Reflection.

Covalent Bonding Covalent Bond: –Compound formed through the sharing of electrons between two Nonmetals (Nonmetal—Nonmetal) –**Hydrogen (H) is included as a Nonmetal!

Eg. Draw the electron-dot structure of a.)H 2 and b.)NaCl H 2 NaCl Covalent Bonding

Molecule – A covalently bonded compound. Q: Which of the following are molecules? a.) NaCl b.) Zn 3 P 2 c.) CO 2 d.) Al 2 S 3 Q: Which of the above are salts?

Q.2.: What are two differences between an Ionic bond and a Covalent bond? (see notes)

Types of Covalent Bonding 2 Types of Covalent Bonding: a.) Nonpolar Covalent Bonding b.) Polar Covalent Bonding *** “Whoever is stronger (higher E.N.) controls the electrons the longest!”

Nonpolar Covalent Bonding A.) Nonpolar Covalent Bonding: (“NO poles”) EQUAL sharing of electrons (link)link Same electronegativity –(Therefore, same element)

Nonpolar Covalent Bonding (cont’d) Diatomic Molecules = 2 atoms of the same element covalently bonded. Eg. H 2 ***All Diatomic Molecules: “ BrINClHOF ” Br 2 I 2 N 2 Cl 2 H 2 O 2 F 2

Drawing Molecules ** 1 bond = ___ electrons = ___ electron pair(s) **

Drawing Molecules (cont’d) Single Covalent Bond = ____electrons (___pair) are shared equally. Double Covalent Bond = ____electrons (____pairs) are shared equally. Triple Covalent Bond = –____ electrons (____ pairs) are shared equally.

Drawing Molecules (cont’d) Eg. Draw each of the following and tell if it has a Single, Double, or Triple Covalent Bond. **Hint: Determine how many bonds each element can form!** 1.) F 2 2.) Br 2 3.) O 2 4.) N 2

***Nonpolar Molecular shapes = LINEAR Linear -

Polar Covalent Bonding Polar Covalent Bonds: (2 poles) –UNEQUAL sharing of electrons b/t atoms with different E.N. –Eg. HF H F (show E.N. for each) *** δ = slight charge from unequal sharing ***

Polar Covalent Bonding (cont’d) H F (show E.N. for each) Q.1: Which has a slight (-) charge (δ-)? Which has a slight (+) charge (δ+)? δ- =δ+ = Polar Covalent Bonds

Drawing Molecules (cont’d) Rule for covalent bonds w/ more than 2 atoms: ***Atom (element) that needs the most electrons will be in center!***

Formula Electron-dot diagram ShapePolar or Nonpolar? F2F2 δ - = δ + = HFδ - = δ + = CH 4 δ - = δ + = H2OH2Oδ - = δ + = H 3 N (NH 3 ) δ - = δ + =

HW a.): –Covalent Bond packet. Answer questions on the last sheet (Answer sheet). HW b.): –Study for quiz tomorrow (Covalent Bonding)

FormulaElectron Dot structure Shape Bond type (polar or nonpolar) H2OH2O CO 2 CCl 4 PH 3 (H 3 P)

Drawing Polyatomic Ions (Table E) All polyatomic ions on Table E are bonded covalently Follow SAME procedure for drawing covalent molecules Include a.)brackets and b.)charge (add or subtract electrons accordingly).

Formula Electron Dot structureShape Bond type (polar or nonpolar) H3O+H3O+ CN - SO 4 -2 PO 4 -3

Q.1: Label the following compounds as ionic, covalent, or both. Formula Ionic, covalent, or both?Why? NaI CaCO 3 C2H6C2H6 NaNO 3 H2H2

Types of Covalent Molecules Review: –2 Types of Covalent Bonds: a.) Polarb.) Nonpolar –Determined by E.N. 2 Types of Covalent Molecules: a.) Polarb.) Nonpolar –Determined by shape (symmetrical or asymmetrical)

Nonpolar Molecules A.) Nonpolar Molecules: 1.) Symmetrical (equal distribution of charges) –Mirror image in both directions (make dotted lines (up/down, left/right) through center.) Eg. Cl 2, CH 4, CO 2

Polar Molecules B.) Polar Molecules: 1.) Asymmetrical (unequal distribution of charges) –Not a complete mirror image (one direction only) Eg. H 2 O, NH 3, HF

FormulaElectron-dot Structure ShapeBond Type: Polar or Nonpolar Molecule Type: Polar or Nonpolar Cl 2 H2OH2O CO 2 CCl 4 NH 3

Review Questions: Q.1: Which of the following contains the most polar bond? a.) HF b.) HCl c.) HBr d.) HI

Review Questions: Matching 1.) Contains an ionic bond.A.) NaI 2.) Is nonpolar because all its bonds are nonpolar. B.) O 2 3.) A nonpolar molecule that contains polar bonds. C.) NH 3 4.) A polar molecule that contains polar bonds. D.) CO 2