1. Chemistry – Nov 28, 2016 P3 Challenge- Today’s Objective –
Identify the ion formed by each of the following elements:
1) Potassium, K
2) Chlorine, Cl
3) Zinc, Zn
Today’s Objective –
Ionic Compounds (Get out your colored periodic table)

2. Chemistry – Nov 28, 2016 Objective –
Ionic compound identification
Ionic compound formation
Ionic compound nomenclature
Assignment: Ionic Compounds Worksheet
Agenda
Valence electrons
Identifying types of compounds
Writing ionic formulas
Type I Ionic Nomenclature
Type II Ionic Nomenclature
Polyatomic ions

3. Valence Electrons
The outermost electrons of an atom will be located in the s and p orbitals with the highest principle quantum number. These are the valence electrons. All other electrons are core electrons.
Because the s subshell can carry 2 electrons and the p subshell can carry 6 electrons, the maximum number of valence electrons is 8, an octet.
A completed octet of valence electrons is the most stable configuration for an atom and explains why atoms form the ions that they do.

4. Compound formation – two methods
Ionic compounds form between metal and nonmetal elements by transferring electrons
Cation (metal ion) and anion (nonmetal ion)
Both cation and anions achieve completed octets
Two metal elements do not form compounds
Two nonmetal elements can form molecular compounds by sharing electrons
Both nonmetals get surrounded by 8 electrons

5. Chemical Formulas Chemical Formula tells number and types of elements
Ionic – formula unit; a representative sample of elements in lattice
Molecular – formula shows number and type of atoms in one molecule

6. Writing Formulas
Because compounds are electrically neutral, one can determine the formula of a compound this way:
The charge on the cation becomes the subscript on the anion.
The charge on the anion becomes the subscript on the cation.
If these subscripts are not in the lowest whole-number ratio, divide them by the greatest common factor.
“Switch, Drop and Reduce”

7. Writing Formulas of Ionic Compounds
Predict ionic compounds that form using the exponent switch and reduce process to create a neutral formula.
Formula always written with cation (metal) first
Ex: compound formed by barium and chlorine
Ex: compound formed by aluminum and oxygen
Ex: compound formed by sulfur and sodium
Ex: compound formed by Fe+2 and oxygen

8. Polyatomic Ions and compounds
Often two or more atoms form a group that has a collective charge.
Memorize the polyatomic ions (see next slide).
Make flash cards. Seriously.
NEVER change the formula of a polyatomic ion
Imagine a shrink-wrap packaging goes around the number and types of atoms and you cannot break up this bundle
Polyatomic ions form ionic compounds.
Ex: sodium and carbonate Na+ and CO Na2CO3
Ex: calcium and nitrite Use parentheses: Ca2+ and NO Ca(NO2)2

10. Three types of ionic compounds
Type 1 - Binary compound (contains only two elements) and cation charge is known because atom can form only one type of ion.
Metal forms only one type of ion: Groups 1A, 2A, Al3+, Ga3+, Zn2+, Cd2+, and Ag+
Type 2 – Binary compound with variable charge cations.
Transition metals and representative metals.
Type 3 – Polyatomic ion compound contains three or more elements contained within one or two polyatomic ions.

11. Type 1 Ionic Compounds
Formed by electron transfer from a metal to a nonmetal
Metal forms only one type of ion: Groups 1A, 2A, Al3+, Ga3+, Zn2+, Cd2+, and Ag+
Name as metal nonmetalide
Name
Formula
sodium chloride
KBr
calcium oxide
Al2O3
lithium fluoride
ZnI2
beryllium nitride
Ag2S

12. Type 2 Ionic compounds – Transition Metals
Most transition metals and group metals form multiple ions.
Cr, Fe and Co form 2+ and 3+ ions
Cu forms 1+ and 2+ ions
Sn, Pb form 2+ and 4+ ions
Mercury (II) is Hg2+, while Mercury (I) is Hg22+
Named as metal (roman numeral for charge on metal) nonmetalide
Name
Formula
lead (II) oxide
CuO
tin (IV) fluride
Hg2S
copper (I) bromide
CoP
iron (III) selenide
Cr3N2

13. Type 3 Ionic compounds – polyatomic ions
Formula will have more than two elements
Often includes oxygen
Often includes () around a polyatomic ion
Name as cation anion
Name
Formula
sodium carbonate
CuOH
tin (II) cyanide
Mg(ClO2)2
ammonium nitrate
FePO4
barium sulfate
LiN02

14. Exit Slip - Homework Exit Slip:
Name Ca(OH)2
Write the formula for Iron (II) sulfate
What’s Due? (Pending assignments to complete.)
Ionic Compounds Worksheet
What’s Next? (How to prepare for the next day)
Read Holt p