Chemical BondingHonor Chemistry

Overview of Types of Bonds

• Metal and Nonmetals = ionic bond

• Nonmetal and Nonmetal= covalent bond

• Both = Combinations of nonmetal group (polyatomic) and metal

• Metal and Metal = metallic bond

What are covalent bonds•A covalent bond is formed by _________ pairs of _____________. It is the stable balance force of __________ between the nucleus and the electrons and the force of repulsion between the two _________.

•The __________ occurs at the point where the potential energy is the lowest.

What are single, double and triple bonds?•A single bond results from _____________ 1 pair (2 electrons).

•A double bond results from sharing _____________ pairs (4 electrons).

•A triple bond results from sharing 3 pair ( ______ electrons).

What are the characteristics of covalent compounds?•Gases, liquids or solids made of molecules.

•Low melting and boiling points

•Poor conductors in all phases

Naming

•The first element is given using its name

•The second element is name likes its anion (with –ide)

•Prefixes are added to tell the number of atoms present for each.

•Mono- is not used to name the first element.

The prefixes (memorize)• Mono- 1

• Di- 2

• Tri- 3

• Tetra- 4

• Penta- 5

• Hexa- 6

• Hepta- 7

• Octa- 8

• Nona- 9

• Deca- 10

Examples

• dinitrogen difluoride:

• carbon tetrachloride

ION BONDS LEQ’S & OBJECTIVES:• What is an ionic bond and how does it form?

• What are the properties of ionic compounds?

• How are ionic formulas written?

• How are ionic compounds named?

• Use know and use the identified vocabulary.

• Determine the number of valance electron for an element in the representative families and the transition metal identified.

• Apply the octet rule to an element.

• Explain how ions form.• Write the chemical formula • Name ionic compounds with

2 elements.• Describe the properties of

an ionic compound.

Ionic Bonds (

Ionic bonds are formed from the electrostatic force between ________ with opposite _______________ that makes them “stick” together.

The ions are formed when one or more ______________ from one atom are ___________ to another. The ion that loses an electron is a ____________ and has a ________________ charge. The ion that gains an electron is a _______________ and has a ______________ charge.

Metals form _____________; Nonmetals form_____________.

Ionic compounds form ionic crystals because ________________

The simplest ratio that ions combine in is _____________________.

Give two examples:

How do you know what ions are formed?•The octet rule states: (p188) ________________________________________________________________________________________________• Look at the diagrams of electron configuration change in sodium (p 189) and oxygen (p192).

• For each representative group find the charge of the ion produced

Charges• You must MEMORIZE the charges of the representative groups.

Group 1 = +1 Group 2 = +2 Group 13 = +3 Group 15 = -3 Group 16 = -2 Group 17 = -1

• Most Transition Metals can have more than one charge, but a few have only one cation, so in addition you need to MEMORIZE: Zn +2 Ag +1 Cd +2

Writing Formulas

• Compounds have NO charge, so

Total Positive Charge = Total Negative Charge

Example: Ba+2 and O-2

K+1 and S-2

Ca+2 and Cl-1

Fe+3 and Br-1

Cr+3 and O-2

Names of Ions(We will only learn the modern Stock names)

For metals in the group 1, 2 and the metals that only have one cation, ust say the name. Al +3 = aluminum cation

For metals with more than one cation, the name is followed by a Roman number giving the charge. Fe+2 = Iron (II)= “iron two cation”

For nonmetals keep the stem of the element name and add –ide. Cl-1 = chloride anion

To Name a Compound: name the cation and the anion. CuCl2 = Copper(II) Chloride *Notice: the 2 in the name is NOT the number of ions in the compound!

Practice NamingBa+2 and O-2

K+1 and S-2

Ca+2 and Cl-1

Fe+3 and Br-1

Cr+3 and O-2

Properties of Ionic Compounds•Crystalline Solids at Room Temperature•High Melting Point•Conductors if molten or in solution

Crystalline Structure

High Melting Point

Conducts Electricity when molten or in solution.

Polyatomic Ion•A covalently bonded group of atoms that has a charge and behaves as a unit.

Master List• You have a list of ions that you will be able to use on practice and tests but it is helpful to recognize a few things: Most polyatomic ions are anions; ammonium is the exception.

Most do end in –ate or ite; the exception are cyanide, peroxide, and hydroxide.

A family has the same charge; oxides of sulfur are -2, oxides of nitrogen are -1.

Examples• Potassium chlorate

• Iron(II) nitrate

• Zinc phosphate

• Barium hydoxide

Polar Bonds and Molecules•Nonpolar share the electrons equally

•Polar bond is a covalent bond where the electrons are shared unequally resulting in regions of charge.

•The difference in electronegativity determines the bond type.

How do you know?