Chapter 8 Ionic Compounds and Metals

Vocabularyoctet rule: atoms tend to gain, lose, or share electrons in order to acquire eight valence electrons

New Vocab - chemical bondcationanionMain Idea: Ions are formed when atoms gain or lose valence electrons to achieve a stable octet electron configuration. Review Valence Electrons are…?• The electrons responsible for the chemical properties of atoms, and are those in the

____________energy level.• The ___and ___electrons in the outer energy level

– the highest ________________energy level _________________________– are those in the energy levels ____________.

Keeping Track of Electrons• Atoms in the same group...

– Have the ____________________ electron configuration.– Have the ____________________ electrons.

• The number of valence electrons are easily determined. – It is given by the ______________________ for a ______________________element– Example: Group 2A: Be, Mg, Ca, etc. have 2 valence electrons

• The ____________ Rule– In Chapter 6, we learned that noble gases are __________________ in chemical

reactions– In 1916, Gilbert Lewis used this fact to explain why atoms form certain kinds of

________ and ___________________– In forming compounds, atoms tend to achieve a ___________________ configuration;

___in the outer level is stable – full ___and____ sublevels– Each noble gas (except _____, which has 2) has ___________________ in the outer level

• ____________ (aka electron) ________ diagrams are…– A way of showing & keeping track of _______________ electrons.– Write the symbol - it represents the nucleus and inner (core) electrons – Put one dot for each valence electron (__________________)– They don’t pair up until they have to (_____________ rule)– Example – Nitrogen– Nitrogen has ______valence electrons to show.

• First we write the symbol.• Then add 1 electron at a time to each side.• Now they are forced to pair up.

6.1 Valence Electrons and Chemical Bonds• A __________________________ is the ______________ that holds two atoms together.

– Chemical bonds form by the _________________ between the positive nucleus of one atom and the negative electrons of another atom.

– Atom’s try to form the octet—the stable arrangement of eight valence electrons in the outer energy level—by gaining or losing valence electrons.

Positive Ion Formation • Metals __________ electrons to attain a noble gas configuration.• They make __________________ions (______________)• If we look at the electron configuration, it makes sense to lose electrons:• This is a noble gas configuration with 8 electrons in the outer level.

Electron Dots For Cations• Metals will have few valence electrons (usually 3 or less);

– calcium has only 2 valence electrons– Example:

• NO DOTS are now shown for the cation.• A positively charged ion is called a cation.• Metals are reactive because they lose valence electrons easily.• Transition metals commonly form 2+ or 3+ ions, but can form greater than 3+ ions.• Other relatively stable electron arrangements are referred to as pseudo-noble gas

configurations.

Negative Ion Formation • An___________ is a ___________________ charged ion.• The figure shown here illustrates chlorine gaining an electron to

become a chlorine ion. (Chloride)• Nonmetal ions gain the number of electrons required to fill an octet.• Some nonmetals can gain or lose electrons to complete an octet.

Electron Configurations: Anions• Nonmetals __________ electrons to attain noble gas configuration.• They make negative ions (anions)• ___________________ are ions from chlorine or other halogens that gain electrons

Electron Dots For Anions• Nonmetals will have many valence electrons (usually 5 or more)• They will ___________electrons to fill outer shell.

– Example:

– This is called the “phosphide ion”, and should show dots)

8.2 Ionic bonds and Ionic compoundsVocabulary

Review– _____________________: a chemical combination of two or more different elements

New– ionic bond– ionic compound– crystal lattice– electrolyte– lattice energy

Main Idea - Oppositely charged ions attract each other, forming electrically neutral ionic compounds.

Formation of an Ionic Bond• The ____________________________ that holds oppositely charged particles together in an

ionic compound is called an ____________________.• Compounds that contain ionic bonds are called __________________________.

• Made from: a ________________with an ____________________• _________________________________________ contain only two different elements

—a metallic cation and a nonmetallic anion.• Anions and cations are held together by __________________ charges (+ and -)• Ionic compounds are called _______________.• Simplest ratio of elements in an ionic compound is called the _________________________ . • The bond is formed through the ___________________ of electrons (lose and gain)• Electrons are transferred to achieve noble gas configuration.

Ionic Bonding Example (NaCl) The metal (sodium) tends to ___________ its one electron from the outer level. The nonmetal (chlorine) needs to ______________ one more to fill its outer level, and

will __________________the one electron that sodium is going to lose. Note: Remember that ________________ are now shown for the ________________!

Ionic Bonding Example (Ca and P)• All the electrons must be accounted for , and each atom will have a noble gas configuration

(which is stable).

This is a ___________________________, which shows the kinds and numbers of _____________ in the smallest representative particle of the substance.

For an ionic compound, the smallest _______________________________ is called a Formula Unit

Properties of Ionic Compounds• Positive and negative ions exist in a _____________ determined by the number of electrons

transferred from the metal atom to the non-metal atom.• The repeating_______________ of particle packing in an ionic compound

is called an ________________________.• The strong attractions among the positive and negative ions

result in the formation of the ____________________________. • A crystal lattice is the three-dimensional geometric arrangement

of particles, and is responsible for the ____________________________________________________.

This figure demonstrates how and why crystals break when an external force is applied.

• Melting point, boiling point, and hardness depend on the strength of the attraction.• In a solid, ions are _______________ into position and electrons cannot flow freely—solid ions

are ____________ conductors of electricity.• Liquid ions or ions in ____________________solution have electrons that are free to move, so

they ________________________________ easily.• An ion in aqueous solution that conducts electricity is an ______________________.

Summary of Properties of Ionic Compounds1. Crystalline solids - a regular repeating arrangement of ions in the solid:

– Ions are strongly bonded together.– Structure is rigid.

2. High melting points3. High boiling points

Energy and the Ionic Bond• Reactions that _________________energy are ______________________.• Reactions that _________________ energy are ______________________.

8.3 Names and formulas for Ionic Compounds

Vocabularyformula unitmonatomic ionoxidation numberpolyatomic ionoxyanion

Main Idea - In written names and formulas for ionic compounds, the cation appears first, followed by the anion.

Predicting Ionic Charges

Formulas for Ionic Compounds• When writing names and formulas for ionic compounds, the _____________ appears

____________followed by the anion.• Chemists around the world need to communicate with one another, so a

_____________________________________ of naming compounds was developed.

Naming cations Two methods can clarify when more than one charge is possible:

_________________________ – uses roman numerals in parenthesis to indicate the numerical value

_________________________ – uses root word with suffixes (-ous, -ic)• Does not give true value

We will use the ____________________________. Cation - if the charge is always the same (like in the Group ___metals) just write the name of the

metal. _____________________ metals can have more than one type of charge.

Indicate their___________________as a ____________________________ in parenthesis after the name of the metal

Practice by naming these:Na1+

Ca2+

Al3+

Fe3+

Fe2+

Pb2+

Li1+

• Write symbols for these:Potassium ionMagnesium ion Copper (II) ionChromium (VI) ionBarium ionOsmium (II) ion

Naming Anions• Anions are _______________ the same charge for a given element• Change the monatomic element ending to – ________• F1- a Fluorine atom will become a Fluoride ion.• Practice by naming these:

Cl1-

N3-

Br1-

O2-

Ga3+

• Write symbols for these:Sulfide ionIodide ionPhosphide ionStrontium ion

Formulas for Ionic Compounds• A formula unit represents the simplest ratio of the ions involved.• Monatomic ions are one-atom ions.• Oxidation number, or oxidation state,

is the charge of a monatomic ion.

• The symbol for the cation is always written first, followed by the symbol of the anion.• ______________________represent the ___________________________________ of each

element in an ionic compound.• The __________________________ must equal _______________ in an ionic compound.• Polyatomic ions are ions made up of _______________________________________.• Never change subscripts of polyatomic ions, place in parentheses and write the appropriate

subscript outside the parentheses.• If the polyatomic ion begins with H, then combine the word hydrogen with the other polyatomic

ion present:

H1+ + CO32- → HCO3

1-

_________________ + ________________ → _______________________________

Names for Ions and Ionic Compounds• An oxyanion is a polyatomic ion composed of an element (usually a non-metal), bonded to one

or more oxygen atoms.

• ____________________________________ is a systematic way of naming compounds.– Name the cation followed by the anion.– For monatomic cations use the element name.– For monatomic anions, use the root element name and the suffix –ide.– To distinguish between different oxidation states of the same element, the oxidation

state is written in parentheses after the name of the cation.– When the compound contains a polyatomic ion, name the cation followed by the name

of the polyatomic ion.

Writing Ionic Compound Formulas1. Write the formulas for the cation and anion, including ________________!2. Check to see if charges are __________________. 3. Balance charges , if necessary, using__________________. Use ________________________ if you need more than one of a polyatomic ion.

Binary Compound Examples:1. Sodium Chloride2. Calcium Chloride3. Calcium Sulfide4. Aluminum Nitride5. Aluminum Oxide

Examples With Polyatomics

1. Iron III Bromide2. Chromium VI Nitride3. Silver I Nitrate4. Ammonium Chloride5. Strontium Phosphate6. Ammonium Carbonate7. Osmium V Oxalate

Things to look for when naming ionic compounds:1) If anions end in -ide they are probably off the periodic table (Monoatomic)2) If anion ends in -ate or –ite, then it IS polyatomic

8.4 Metallic bonding and the properties of metals

VocabularyReview

physical property: a characteristic of matter that can be observed or measured without altering the sample’s composition

Newelectron sea modeldelocalized electronmetallic bondAlloy

Main Idea - Metals form crystal lattices and can be modeled as cations surrounded by a “sea” of freely moving valence electrons.

• Pure Metals are not ionic but share several properties with ionic compounds.• Metals also form lattices in the solid state, where 8 to 12 other atoms closely surround each

metal atom.• Within the crowded lattice, the ___________________________ of metal atoms

__________________.• The electron sea model proposes that all metal atoms in a metallic solid contribute their valence

electrons to form a "sea" of electrons.• The electrons are free to move around and are referred to as delocalized electrons, forming a

metallic cation.• Metals hold on to their valence electrons ____________________________.• Atoms are _______________________ (like marble magnets)

• A metallic bond is the attraction of an metallic cation for delocalized electrons.

• ____________________________ are much more ___________________than melting points because of the energy required to separate atoms from the groups of cations and electrons.

• Metals are __________________ because they can be hammered into sheets.• Metals are __________________ because they can be drawn into wires.• Mobile electrons allow atoms to _______________by, sort of like ball bearings in oil.• Mobile electrons around cations make metals good ____________________ of electricity and

heat.• As the number of delocalized electrons increases, so does hardness and strength.

Metal Alloys• An alloy is a____________________of elements that has metallic properties.• The properties of alloys differ from the elements they contain.

– Properties are often superior to the pure element– _________________ silver (92.5% Ag, 7.5% Cu) is ________________and more durable

than pure Ag, but still soft enough to make jewelry and tableware– _________________ are very important alloys

• corrosion resistant, ductility, hardness, toughness, cost