Chemical Bonding (Ionic, Covalent and

Metallic)

Name_________________

Quiz Date _____________ Test Date______________

____________________ is the mutual attraction between the nucleus and valence electrons of different atoms. Atoms bond to become more ______________!

What are the 3 bond types? 1) Def: ____________________________________________________ ________________________________________________________ ________________________________________________________ 2) Def: ____________________________________________________ ________________________________________________________ ________________________________________________________ 3) Def: ____________________________________________________ ________________________________________________________

Types of Covalent Bonds 1) Equal sharing of electrons between atoms in a compound, no positive or negative poles exist = _________________________________________ 2) Unequal sharing of electrons within a molecule, positive and negative ends exist = _________________________________________________

Occurs Between Role of the Electrons

Example

Covalent Bonding

Determine Bond Type from Electronegativity Differences Try It – Practice Problems: Determine the BOND Polarity: 1) H – S (2.2, 2.6) 5) Cs – S (0.8, 2.6) 2) S – Cl (2.6,3.2) 6) O – O (3.4,3.4) 3) Rb – Se (0.8,2.6) 7) F – I (4.0,2.7) 4) C – I (2.6,2.7) 8) Ca – N (1.0,3.0) Other Types of Covalent Bonds:

Memorize this Diagram!!

Key Terms to Know: *________________________ = neutral compound consisting of nonmetals covalently bonded *_________________________________ = smallest representative unit of a molecular compound, can exist independently

What are these elements called? Def: ___________________________ ___________________________ ___________________________ Define these: Bond Length:_________________________________________________ _____________________________________________________________ Bond Angle:__________________________________________________ _____________________________________________________________ Bond Energy:________________________________________________ _____________________________________________________________

As bond length increases, bond energy decreases. As bond length increases, bond strength decreases.

**Think about it!!!** What relationship do each of the above have? What is the relationship between bond length and bond strength for each?

Memorize These!!

What are polyatomic ions? DEF: Ex:

Properties of Covalent Compounds Dot Diagrams and Structural Formulas - Molecules It is important to follow the Octet Rule - ____________________________ _____________________________________________________________ The following elements are exceptions to this rule: (MEMORIZE THESE!) Let’s Try It – Practice Problems! Examples:

1. NH3

2. CH4

3. H2O

4. BF3

5. CO2 VSPER Theory: ______________________________________________ _____________________________________________________________ _____________________________________________________________ Define and draw a picture for each of the following: Lone pair: Shared pair: Def: Def: Picture:

Molecular Geometry (Shapes)

VSEPR - Shapes Table ****The five shapes you need to know are…****

Shape # Bonds to

Central Atom # Lone Pairs to Central Atom

Examples

Linear 2 atoms together or 2

bonds to central atom

0

Bent 2 2

2 1

Trigonal Planar 3 0

Trigonal Pyramidal

3 1

Tetrahedral 4 0

Let’s Try It – Practice Problems! 1. NH3 2. CH4 3. H2O 4. BF3 5. CO2

Molecular polarity: What does Molecular Polarity depend upon? 1) 2) 3) Molecular polarity influences intermolecular forces. Nonpolar molecule: Polar molecule: Polar or non-polar?

____________ _________ ______________

Think about it: Review Questions for studying on your own 1) What shapes are ALWAYS polar molecules?

2) What guarantees that a compound will be polar?

Molecular Polarity

Intermolecular Forces: ________________________________________ _____________________________________________________________ _____________________________________________________________ The 3 intermolecular forces are 1) 2) 3) Type Definition Examples

Let’s Try It! – Determine the IMF(s) Present H2O Molecular Polarity =

Dispersion Forces Dipole-Dipole H-Bonding

SCl2

Intermolecular Forces The glue that holds the molecules together

PF3

CF4 Relating properties to IMF’s:

1. Stronger bonds/imf’s

2. Weaker bonds/imf’s

3. Solubility Let’s Try It! - Practice Problems

1. Would the following be soluble in each other? - H2O and CF4

2. Which would have the higher boiling point? - H2O or PF3

3. Which would have the lower melting point? - CO2 or NH3

Definition Role of the

Electrons Example

How does this picture explain metallic bonding? ________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Properties of Metallic Compounds

Metallic Bonding

The strength of a metallic bond is determined by number of outer electrons Softer metals can be combined with harder metals. The strongest metals are the transition metals

Definition Role of the

Electrons Example

The simplest combining ratio of ions in a compound that does not exist independently is called a _______________________________. Determining the formula unit

(Remember that the compound is neutral overall = no charge) Let’s try it! Determine the formula unit for each! 1) Potassium and Fluorine 2) Calcium and Iodine 3) Magnesium and Nitrogen 4) Calcium and nitrate 5) Sodium and phosphate

Ionic Bonding

Drawing Structures - Dot Diagrams for Ionic Compounds Ex: NaCl Ex: CaBr2 Ionic Compounds form solid crystals. Crystal lattice: ___________________________________________ _______________________________________________________

Lattice energy: ___________________________________________ ________________________________________________________ ________________________________________________________

Crystal Lattice – all (+) ions are completely surrounded by (-) ions and vice versa

Properties of Ionic Compounds