Homework Assignment: In Text page 180 1,2 Page 183 3, 8 Page 184 13, 14 Page 185 21 Needs 37 min or so

Homework Review Study guide – Concept Review page 33 and 34. The support reading is page 158-165 in the text.

Today: Chem talk We will learn about the different kinds of ions How to name ions for use in compound naming.

The Different Kinds of Ions 1. Monatomic Ions---Ions having only one atom Two kinds: Positive or negative a. only one charge-ex: Na+, Ca2+ Cl-1, O-2 b. more than one charge ex: Fe2+, Fe3+ 2. Polyatomic Ions---Ions made of more than one atom, also positive or negative.

Let’s start with monatomic Ions—ions consisting of one atom. Rules: 1. metallic elements tend to lose electrons 2. nonmetals tend to gain electrons Many form ions with only one charge. (Note: group 14 and group 18 generally do not form ions) For simple ions, there are two ways to name: Positive ions—use their elemental name. So a Na+1 is called a sodium ion. Zn2+ is called a zinc ion. Negative ions have the name of the element with end changed to end in “ide”. Example: Cl-1 is called a chloride ion. P-3 is called a phosphide ion

Some, however, can form more than one ion. Go in the reference table to iron. iron can form a 2+ or 3+ ion. How would you know which one to use? copper can form a 1+ or 2+ We need an additional way to tell you which one it is because you have no way of knowing.

Iron(III) is Fe3+ Lead(IV) is Pb4+ Cobalt(II) is Co 2+ To eliminate confusion, a simple system was created to name the ion. It is called the Stock system and it uses Roman Numerals to tell you what the ion charge is. Rule 1: If a plus ion forms only one charge—no roman numeral. Rule 2: If a plus ion forms more than one charge—a roman numeral is given indicating the charge. Roman numerals: I = 1, II = 2, III = 3, IV = 4, V = 5 When written, the roman numeral is placed in a parenthesis. you must be told because there is no other way to know!! Examples: Iron(III) is Fe3+ Lead(IV) is Pb4+ Cobalt(II) is Co 2+

For Regents Chemistry, where are the ions found? Ions that form only one charge number. Group 1, group 2, group 13, group 16, group 17—look for the number in the upper right corner. Group 15 is usually minus 3. Ions that form more than one charge number. There are eight: Cu, Fe, Hg, Pb, Sn, Cr, Mn, and Co They are mostly transition metals.

What is my name? Cu2+ Copper(II) Lead(II) Pb2+ Fe3+ Iron(III)

Polyatomic Ions Polyatomic Ions are groups of atoms that carry a set charge, but behave as a single ion. For regents chemistry, they are covalently bonded atoms that hold a charge—either positive or negative. They act as a single unit. Most are negative but three are positive.

A table of common polyatomic ions Let’s look at some. A table of common polyatomic ions

They all have names as found in the reference table, page 1. What is my name? Ca2+ Fe2+ SO4-2 MnO4- NH4+ Calcium ion Iron(II) ion Sulfate ion Permanganate ion Ammonium ion

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