1. Crux of the Matter Unit 4
Chapters 7 and 8

2. Ionic Compounds A transfer of electrons creates a strong bond
Occurs between a metal and a nonmetal or a metal and a polyatomic ion- held together by electrostatic force
Compounds form in the simplest whole number ratios
Creates true ions- cation (+) and anion (-)
All ionic compounds are polar and called a formula unit
Alkali and alkaline metal compounds combined with halogens are called salts

3. Properties of Ionic Compounds
Compounds are solids at room temperature
Crystalline solids (made of ions) 6 basic shapes
High melting and boiling points – due to the lattice energy- smaller the ions involved the stronger the bonds
Conduct electricity when melted or dissolved in water- electrolytes

4. Properties Continued
Many soluble in water ( the universal polar solvent) but not in nonpolar liquid
The formation of ionic compounds is always exothermic

5. Criss Cross

6. Naming ionic compounds

7. Lewis Dot Diagrams of Ionic Compounds

11. Covalent Compounds Created from sharing electrons
Occurs between a nonmetal and a nonmetal or a nonmetal and a polyatomic ion
Covalent compounds can either be polar or nonpolar
Covalent compounds are called molecules
Formulas are in whole number ratios, but do not need to be simplified
There can be single, double and triple bonds
Diatomic elements-OHNoHalogens

12. Properties of covalent compounds
Bonds have different lengths- the shorter the bond the more energy required to break it
Triple bonds are stronger than double bonds, and double bonds are stronger than single bonds
Compounds are usually gases or liquids, some however can be solids
Low melting and boiling points than ionic compounds
Poor electrical conductors in all phases
Compounds are either polar or nonpolar- to dissolve, use the rule “like dissolves like”

13. A molecule’s shape

14. Lewis Dot Diagrams and Structural Diagrams

15. Total Pairs
Electrons Shared Pairs
Unshared Pairs
General Shape 4
tetrahedral 3 1
pyramidal 2
bent
linear
trigonal planar

16. Determining a molecule’s shape

17. Hybridization

18. Determining the polarity of a molecule

19. Naming Molecules

20. Naming Acids

21. Resonance Structures occur when molecules can arrange themselves to form bonds in different areas yet still obey the octect rule.

22. Metallic Bonds occur because the metals’ nuclei becomes surrounded by a sea of electron
This gives metals their physical properties of malleability and ductility

23. Dipole bonds- created from equal but opposite charges
London dispersion forces-weak intermolecular forces that occur between nonpolar molecules and is caused by the movement of electrons
Hydrogen Bonds-occur between hydrogen and a higher electronegative element (O,N, halogens)