Warm Up

Iron can form two different oxides ….. Fe2O3 and FeO. We know for absolute certainty that an oxygen anion always has a -2 charge. What is going on here … how can there be two iron oxides???

Warm Up-Answer

-Turns out we need to balance charges such that compound has zero charge

- So in FeO if we have 1 oxygen atom that is always a -2 charge then (1 O atom)(-2) = -2 …..

so then our Fe must have a +2 charge to balance out (1 Fe atom)(+2) = +2 …. +2 and -2 cancel out

-With Fe2O3 we have (3 O atoms)(-2) = -6So (2 Fe)(???) = +6The answer is of course +3 ….

Warm Up - Answer

FeO has a +2 charged iron cationFe2O3 has a +3 charged iron cation

Ion Formation and Naming Ions

Chapter 7.1/9.1

Learning Objectives• You will know what valence electrons are and how

to determine how many.

• You will be able to draw electron dot structures of 1A-8A elements

• You will understand the octet rule and how it leads to stable cations and anions

• You will learn how to name simple anions and cations

• You will understand how to name transition metals and polyatomic ions

Valence Electrons

–Electrons in the highest occupied energy level (s and p only)

–Determines chemical properties of element–Equals the group number (A series)– Involved in chemical bonding

Lewis Dot Structures

–Diagrams that show the valence electrons of an atom using dots

–Also called electron dot structures

Octet Rule

– Atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons

– Goal to be isoelectronic to a noble gas

Special Vocabulary

Isoelectronic–Ions that have the same electron

configuration

Halide ions–When the halogen group elements

become ions (F-, Cl-, Br-, I-)

Monoatomic Ions

Single atom with a positive or negative charge. Occurs when lose (cation) or gain (anion) valence electrons

1A 2A 3A 4A 5A 6A 7A 8A

Li+ Be2+ B3+ N3- O2- F-

Na+ Mg2+ Al3+ P3- S2- Cl-

K+ Ca2+ As3- Se2- Br-

Rb+ Sr2+ I-

Cs+ Ba2+

Naming Cations

Naming of cation usually involves the name of the element plus the word ion

Na+ would be called sodium ion

–Alternative techniques for variable charge ions (transition elements)

Naming Transition Metal Ions

Symbol Modern name

Cu+ Copper(I) ion

Cu2+ Copper(II) ion

Fe2+ Iron(II) ion

Fe3+ Iron(III) ion

Sn2+ Tin(II) ion

Sn4+ Tin(IV) ion

A few transition metals only have one charge and roman numerals are not used … Ag+, Cd2+, Zn2+

Naming Anions

Naming of anion– Monatomic anion ends in –ide

Not chlorine … chloride

Not oxygen … oxide

Not nitrogen … nitride

– Many anions are polyatomic – need to memorize the more common ones … chart I gave you today.

Polyatomic Anions

Ions that are composed of more than one atom. Most are anions (negative charge).

SO42-

sulfateThe names of most polyatomic anions end in –ite or –ate.

Homework

Chapter 7.1 (Read!!) page 193 (#3-9) page 207-208 (#31,32, 62)

Chapter 9.1 (Read!!)page 258 (#4,5,8,9) page 281 (#42-46)