1. Ch 5 Ions and ionic cpds Chemical reactivity:
Depends on electron configuration, noble gas least reactive (s&p filled)
Octet rule: atoms tend to react to fill s&p valence electron shells.

2. Chemical reactivity Alkali metals and halogens most reactive elements
Atoms lose, gain or share electrons to obtain an octet.
Alkali metals: ns1 configuration -> lose one electron (1+ change)
Halogens: ns2p5 configuration -> gain one electron (1- change)
Both reach an octet, filled s & p valence shell.

3. Valence electrons
Use electron configuration to determine # of valence electrons . Look for highest PQ# s & p electrons.
Gain or lose electrons --> stable ion
Lose electrons --> cation (+) charge = # electrons lost
Gain electrons --> anion (-) charge = # electrons gained
Both cases reach an octet.

4. Characteristics of stable ions
Filled s&p orbits of highest energy level
Noble gas configuration, octet
Ions have electric charge
Combine cation w/ anion in cpd
Conduct electric current in water
Transition metals ions w/out complete octet
Have multi oxidation states
All cations.

5. Atoms and ions Different chemical properties.
Metals --> cations, less energy to lose electrons (1 to 3) than to gain (5 to 7)
Nonmetals --> anions, less energy to gain electrons (1 to 3) than lose (5 to 7)
Cations and anions combine to form compounds with very specific properties separate from the metals and nonmetals properties.

6. Ionic bonding and salts
Ionic bond: electrostatic attraction between opposite charges of cations and anions.
Forms solids called salts.
Salt: ionic cpd that forms when a metal atom or a positive radical replaces the hydrogen of an acid
Electrically neutral
Simple whole number ratio based on charge of ions
Distinctive crystal structure
Transferring electrons involve D energy. Overall energy D is exothermic.
Na + E --> Na+ + e Cl + e- --> Cl- + E

7. Salt formation (pg 169 figure 9)
Endothermic (breaking bonds)
1. Na(s) + E --> Na(g) sublimation
2. Na(g) + E --> Na+ + e- ionization E
3. Cl-Cl + E --> 2Cl(g) bond E
Exothermic (bond forming)
4. Cl(g)+ e- --> Cl-(g) + E electron affinity
5. Na+ (g) + Cl-(g) --> NaCl(s) + E lattice E

8. Lattice energy
Energy associated with constructing a crystal lattice relative to the energy of all constituted atoms
Energy released w/ crystal structure of a salt as formed, key to salt formation.
Net energy is exothermic:
Energy to separate ions in water is supplied by water.
If a salt is not soluble, water does not have enough E to break ionic bonds

9. Ionic cpds Minerals of earth’s crust, cations + anion --> salt
Do not consist of molecules
ionic bonds are strong, attraction between opposite charges.
Distinctive properties (pg 171 table 1)
High boiling and melting pts
Solids at room temperature
Conduct electric current (l) or (aq)
Hard and brittle, ions arranged in repeating patterns, layers.--> shatter along cleavage plane.

10. Salt crystals Form repeating patterns --> crystal lattice
Repeating units, reason for crystal shape
Crystal structure depends on size & ratio on ions (pg 174 figure 12)
Salts have ordered packing arrangement
Until cell: smallest repeating unit in a crystal lattice.
Determined by x-ray diffraction crystallography.
Make model of arrangement of unit cells based on diffraction patterns.

11. Names and formulas of ionic cpds
Naming ionic cpds:
Binary salts (2 elements, metal/nonmetal ions)
Cation: name metal, roman numeral if multi oxidation state.
Anion: root word of nonmetal and end in ide.
Writing ionic formulas:
Total positive charge = total negative charge. Net charge of cpd = 0
1. Write symbol & charge of cation & anion
Multiple oxidation state metals-> use roman numeral to indicate charge. (I) (II) (III) (IV) (V) (VI)
2. Reduce if possible
3. Cross over just the number --> subscripts.

12. Practice Write the formula for the following:
Copper (II) oxide, sodium fluoride, zinc chloride, aluminum sulfide, chromium (VI) oxide.
Name the following:
Ca3N2, FeI3, Na2O, AlCl3, SrO, MnO2

13. Polyatomic ions
Ion made of two or more atoms covalently bonded with a net positive or negative charge (pg 178 table 2)
Form ionic bonds with opposite charged ions.
Naming polyatomic ions:
Oxypolyatomic ions
End in ite or ate as determined by # of oxygen's (SO3 2- sulfite, SO4 2- sulfate)
With addition of hydrogen atom (HPO4 2- monohydrogen phosphate)
Thio means replace oxygen with sulfur (S2O3 2- thiosulfate)
Naming or writing formula with polyatomic ion same as before. Use polyatomic name as is.

14. Practice Write the formula for the following:
Aluminum nitrate, magnesium phosphate, ammonium acetate, iron (II) thiosulfate, Copper (I) peroxide.
Name the following:
Ca(NO3)2, CuSO4, CuNO3, Na2CO3, K2Cr2O7