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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
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