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Ionic Compounds and Metals. Chemistry Matter and Change: Chapter 7. BIG IDEA. Atoms in ionic compounds are held together by chemical bonds formed by the attraction of oppositely charged ions. . 7.1 Ion Formation. 7.1 Main Idea.

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ionic compounds and metals

Ionic Compounds and Metals

Chemistry Matter and Change: Chapter 7

big idea
BIG IDEA

Atoms in ionic compounds are held together by chemical bonds formed by the attraction of oppositely charged ions.

7 1 main idea
7.1 Main Idea

Ions are formed when atoms gain or lose valence electrons to achieve a stable octet electron configuration.

7 1 objectives
7.1 Objectives
  • Define a chemical bond.
  • Describe the formation of positive and negative ions
  • Relate ion formation to electron configuration.
review vocabulary concepts
Review Vocabulary & Concepts

Ion

Valence electron

Octet

Electron configuration

Lewis-dot diagrams

Electron affinity

new vocabulary
New Vocabulary

Chemical bond

Ionic bond

Cation

Anion

chemical bond
Chemical Bond
  • The force that holds two atoms together
  • Three types
    • Ionic bonds *Chap 7
    • Metallic bonds *Chap 7
    • Covalent bonds *Chap 8
valence electrons and chemical bonds
Valence Electrons and Chemical Bonds

Each valence electron is represented as a dot around the nuclear core of the element.

valence electrons and chemical bonds1
Valence Electrons and Chemical Bonds
  • The most stable electron configuration for an element is the nearest noble gas.
    • ns2np6
    • Octet
  • Ions gain or lose electrons to achieve noble gas configurations
positive ion formation
Positive Ion Formation

Cation: a positively charged ion

Results when electrons are lost

metal ions
Metal ions
  • Group 1 loses 1 electron

+1 charge

  • Group 2 loses 2 electrons

+2 charge

  • Group 13 loses 3 electrons

+3 charge

  • Groups 3-12 usually lose 2 electrons

Most have +2 charge (range from +1 to +3)

negative ion formation
Negative Ion Formation

Anion: negatively charged ion

Formed when electrons are gained

Non-metals

nonmetal ions
Nonmetal Ions
  • Group 15 gains 3 electrons

3- charge

  • Group 16 gains 2 electrons

2- charge

  • Group 17 gains 1 electron

1- charge

section summary
Section Summary

A chemical bond is the force that holds two atoms together

Some atoms gain or lose electrons to gain a stable configuration; these are called ions

Most stable configurations end: ns2np6.

http://www.youtube.com/watch?v=lODqdhxDtHM&feature=related

sodium
Sodium
  • Electron loss or ionization of sodium atom
  • Na 1s22s22p63s1 → Na+ 1s22s22p6
slide20

Chlorine

  • A gain of one electron gives chlorine an octet and converts a chlorine atom into a chloride ion.
  • It has the same electron configuration as argon
section 7 1 practice 1
Section 7.1 practice #1:

1. How many valence electrons does each of the following atoms have?

gallium

fluorine

selenium

section 7 1 practice 2
Section 7.1 practice #2:

2. For each element below, state (i) the number of valence electrons in the atom, (ii) the electron dot structure, and (iii) the chemical symbol(s) for the most stable ion.

Ba

I

K

section 7 1 practice 3
Section 7.1 practice #3

3. Write the electron configuration for each of the following atoms and ions.

  • K atom
  • K ion

c. Na atom

d. Na ion

e. Phosphorous atom

f. Phosphide ion

section 7 1 practice 4
Section 7.1 practice #4

4. How many electrons will each element gain or lose in forming an ion? State whether the resulting ion is a cation or an anion.

a. strontium (Sr)

b. tellurium (Te)

c. Bromine (Br)

d. aluminum (Al)

e. rubidium (Rb)

f. Phosphorus (P)

7 2 main idea
7.2 Main Idea

Oppositely charged ions attract each other forming electrically neutral ionic compounds.

7 2 objectives
7.2 Objectives

Describe the formation of ionic bonds and the structure of ionic compounds

Generalize about the strength of ionic bonds based on the physical properties of ionic bonds

Categorize ionic bond formation as exothermic or endothermic

review vocabulary concepts1
Review Vocabulary & Concepts

Compound

Chemical bond

Physical property

Chemical property

Electronegativity

new vocabulary1
New Vocabulary

Ionic bond

Ionic compound

Crystal lattice

Binary compound

Electrolyte

formation of an ionic bond
Formation of an Ionic Bond
  • Electrons are exchanged between atoms
    • Increases stability of both
  • Ions are held together by the opposite charges
definition of ionic bond
Definition of Ionic Bond
  • Bond formed between two elements with an electronegativity difference > 1.7
    • Crystallize as sharply defined particles
binary ionic compounds
Binary Ionic Compounds
  • Formed from a metal and a non-metal
  • Contain only two elements
    • Examples
      • NaCl
      • MgO
      • CaCl2
      • Fe2O3
formation of ionic compounds
Formation of Ionic Compounds
  • Net charge on all ions in a compound must be zero (0)!
    • More on this later!!!
properties of ionic compounds
Properties of Ionic Compounds

Anion

Cation

Crystal Lattice: Highly organized crystal of cations and anions

properties of ionic compounds1
Properties of Ionic Compounds

Crystalline shape depends on the ions involved

properties of ionic compounds2
Properties of Ionic Compounds
  • Physical properties
    • Very strong
    • Solid at normal temperatures
      • Very high melting point and boiling point
    • Many have brilliant colors due to transition metals
    • Hard, rigid
    • Brittle
properties of ionic compounds3
Properties of Ionic Compounds
  • Conductivity (ability for electric charge to move through a substance
    • Solids have electrons locked in place
      • Non conductive
    • Aqueous solutions have easily moveable electrons
      • Electrolytes
      • Good conductors
properties of ionic compounds4
Properties of Ionic Compounds

PolarDissolution

Dissolve in water

May have radically different properties than the elements that compose them

properties of ionic compounds5
Properties of Ionic Compounds

Formation of lattice is always exothermic.

section summary1
Section Summary

Ionic compounds contain ionic bonds formed by the attraction of oppositely charged ions.

Ions in an ionic compound are arranged in a repeating pattern called a lattice.

Ionic compounds are electrolytes; they conduct electricity in liquid and aqueous states.

can you
Can you…

Describe the formation of ionic bonds and the structure of ionic compounds

Generalize about the strength of ionic bonds based on the physical properties of ionic bonds

Categorize ionic bond formation as exothermic or endothermic

7 3 big idea
7.3 Big Idea

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

7 3 objectives
7.3 Objectives
  • Relate a formula unit of an ionic compound to its composition
  • Write formulas for ionic compounds and oxyanions.
  • Apply naming conventions to ionic compounds and oxyanions.
review vocabulary concepts2
Review Vocabulary & Concepts

Anion

Cation

Metal

Non-metal

new vocabulary2
New Vocabulary

Formula unit

Monatomic ion

Polyatomic ion

Oxidation number

Oxyanion

describing ionic compounds
Describing Ionic Compounds

Cl-

Cl-

Mg2+

  • Formula unit- simplest way to indicate the composition of an ionic substance
    • NaCl
    • MgCl2
monatomic ions
Monatomic Ions
  • Ions in which only one element is present
    • Na+, Cl-, Mg2+, P3-
oxidation number
Oxidation number
  • Fancy word for “charge”
  • aka oxidation state
  • Transition metals may have multiple oxidation states
    • Must tell the oxidation state
      • Ex: Iron 2+ is Iron II; Iron 3+ is Iron III
formulas for binary ionic compounds
Formulas for Binary Ionic Compounds
  • CxAy
    • C is cation
    • A is anion
    • x number of cations in one unit
    • y is number of anions in one unit
rules for writing formula units
Rules for writing formula units
  • CxAy
    • Cation is always first
    • Anion is always second
  • Net oxidation MUST BE ZERO
tried and true method
Tried and True Method

Write out each ion.

Place oxidation number under each ion

Cross multiply

Reduce to simplest form

write out each ion
Write out each ion.

Example 1:

Sodium and chlorine

Na Cl

place oxidation number under each ion
Place oxidation number under each ion
  • Sodium and chlorine

Na Cl

+1 -1

cross multiply
Cross multiply

Na Cl

1 1

  • Sodium and chlorine

Na Cl

+1 -1

reduce to simplest form
Reduce to simplest form

NaCl

  • Remove any “1”s
      • NaCl
  • Reduce if needed
write out each ion1
Write out each ion.

Iron III and oxygen

Fe O

place oxidation number under each ion1
Place oxidation number under each ion
  • Example 2:
  • Iron III and oxygen

Fe O

3+ 2-

cross multiply1
Cross multiply

Fe O

2 3

  • Iron III and oxygen

Fe O

3+ 2-

reduce to simplest form1
Reduce to simplest form
    • Fe2O3
  • Cannot be reduced
write out each ion2
Write out each ion.
  • Example 3:
  • Magnesium and oxygen

Mg O

place oxidation number under each ion2
Place oxidation number under each ion
  • Magnesium and oxygen

Mg O

2+ 2-

cross multiply2
Cross multiply

Mg O

2 2

  • Magnesium and oxygen

Mg O

2+ 2-

reduce to simplest form2
Reduce to simplest form

Mg2O2

Both subscripts can be divided by 2 so the final formula is

MgO

practice
Practice

Why did we specify some oxidation numbers, but not others?

Silver I and chlorine

Antimony (V) oxide

Aluminum sulfide

Magnesium and fluorine

Iron II and oxygen

Calcium and phosphorus

rules for naming binary ionic compounds
Rules for Naming Binary Ionic Compounds
  • State the name of the cation.
    • (If using a transition metal, you must state the oxidation number if there is more than one possibility.)
  • State the name of the anion, but change the ending to “ide.”
practice1
Practice
  • NaCl
    • Sodium chlorine chloride
  • MgO
    • Magnesium oxide
  • K2S
    • Potassium sulfide
tricky practice
Tricky practice
  • Fe2O3
    • Iron is a transition metal so we need to figure out the charge before we can name the compound.
    • We know oxygen is always -2, so there is an overall charge of -6 from the oxygen
    • That means Iron must supply an overall charge of +6
    • This indicates that iron must have an oxidation number of +3 in this case
tricky practice1
Tricky practice
  • Fe2O3
    • Iron III oxide
  • CuS
  • AgCl* (trick!)
  • H2O
monatomic ions vs polyatomic ions
Monatomic Ions vs polyatomic Ions

Monatomic ion: a one atom ion

Ex. Mg 2+

Polyatomic ion: ions made up of more than atom

Ex. PO43-

oxyanions
Oxyanions
  • Oxyanions- a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms.
  • The ion with the greater number of oxygen atoms ends in –ate.
  • The ion with the fewer number of oxygen atoms ends in –ite.
  • Ex. NO3- NO2-
      • Nitrate Nitrite
take out a sheet of paper
Take out a sheet of paper
  • Directions:
    • Draw 5 by 5 chart.
    • Write 5 metals ions in the left margin
    • Write 5 nonmetal ions on the top
    • Trade charts with the person next to you
    • Fill in the charts by writing the correct formulas for the ionic compounds formed in the square.
    • Hand the chart back to your partner when your done and check each others responses.
    • Once finished, raise your hand and ask Mrs. Chebib to come over and stamp your work for credit
naming polyatomic ions
Naming Polyatomic Ions
  • State the name of the cation.
    • (If using a transition metal, you must state the oxidation number if there is more than one possibility.)
  • Name the anion
practice2
Practice
  • AgNO3
    • Silver nitrate
  • CaCO3
    • Calcium carbonate
  • NH4Cl
    • Ammonium chloride
  • FeSO4
    • Iron II sulfate
writing formulas for ionic compounds with polyatomic ions
Writing formulas for ionic compounds with polyatomic ions

Write out each ion.

Place oxidation number under each ion

Cross multiply

Reduce to simplest form

side note
Side note

Oxyanions are any polyatomic anions that contain oxygen

Your book likes to sound fancy!

writing formulas for ionic compounds with polyatomic ions1
Writing formulas for ionic compounds with polyatomic ions

You may not, under any conditions, change the subscripts within the polyatomic ion when balancing the charge. You may only adjust the number of units of each polyatomic ion!!

Use parentheses to remind yourself that the units go together and cannot be changed.

write out each ion3
Write out each ion.

Potassium permanganate

K (MnO4)

place oxidation number under each ion3
Place oxidation number under each ion

Potassium permanganate

K (MnO4)

+1 -1

cross multiply3
Cross multiply
  • K (MnO4)

1 1

Potassium permanganate

K (MnO4)

+1 -1

reduce to simplest form3
Reduce to simplest form
  • Potassium permanganate is

K(MnO4)

write out each ion4
Write out each ion.

Calcium hydroxide

Ca (OH)

place oxidation number under each ion4
Place oxidation number under each ion
  • Calcium hydroxide

Ca (OH)

+2 -1

cross multiply4
Cross multiply
  • Calcium hydroxide

Ca (OH)

+2 -1

Ca(OH)2

write out each ion5
Write out each ion.

Ammonium phosphate

(NH4) (PO4)

place oxidation number under each ion5
Place oxidation number under each ion

Ammonium phosphate

(NH4) (PO4)

+1 -3

cross multiply5
Cross multiply

Ammonium phosphate

(NH4) (PO4)

+1 -3

(NH4)3(PO4)

practice3
Practice

Sodium nitrite

Calcium sulfate

Aluminum hydroxide

section summary2
Section Summary

A formula unit gives the ration of cations to anions in the ionic compound.

A monatomic ion is formed from one atom.

Roman numerals indicate the oxidation numbers of any element with more than one oxidation number.

section summary3
Section Summary

Polyatomic ions consist of more than one atom and act as a single unit.

To indicate more than one polyatomic ion in a chemical formula, place parentheses around the polyatomic ion and use a subscript outside the parentheses.

can you1
Can you…

Relate a formula unit of an ionic compound to its composition

Write formulas for ionic compounds and oxyanions.

Apply naming conventions to ionic compounds and oxyanions.

7 4 main idea
7.4 Main Idea

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

slide100
7.4

Describe a metallic bond

Relate the electron sea model the physical properties of metals

Define alloys and categorize them into two basic types.

review vocabulary concepts3
Review Vocabulary & Concepts

Physical property

Metal

Malleable

new vocabulary3
New Vocabulary

Electron sea model

Delocalized electron

Metallic bond

Alloy

metallic bonds
Metallic Bonds
  • Lattice structures with freely moving electrons
    • Electrons are not firmly attached to any one nucleus, but instead “visit” many nuclei
metallic bonds1
Metallic Bonds

Attraction of a metallic cation for delocalized electrons

the electron sea
The Electron Sea

Freely moving electrons are referred to as “delocalized” (lacking a location)

Video

slide106

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properties of metals
Properties of Metals
  • Melting and Boiling points
    • Vary greatly
    • Most are moderately high melting points and very high boiling points
properties of metals1
Properties of Metals
  • Malleability, ductility and durability
    • Nuclei move relatively free of each other due to the sea of electrons
properties of metals2
Properties of Metals
  • Thermal and electrical conductivity
    • Delocalized electrons quickly move heat from one part of the metal to other parts
    • Delocalized electrons can move in one direction and create a “current.”
properties of metals3
Properties of Metals
  • Hardness and strength
    • The number of delocalized electrons plays a role in the hardness of the metal
      • More delocalized electrons means a harder metal
      • Sometimes d level electrons are delocalized as well as the s resulting in very hard metals.
metal alloys
Metal Alloys
  • Alloy- a mixture of elements that has metallic properties
    • Characteristics may differ from the “parent” metals
    • Include brass, bronze, 14-carat gold, stainless steel, etc.
types of metal alloys
Types of Metal Alloys
  • Substitutional
    • Some of the atoms from one metal are replaced by atoms of the other metal
    • Ex: brass
types of metal alloys1
Types of Metal Alloys
  • Interstitial
    • Small holes in the lattice are filled by atoms of another element
    • Example: Steel
section summary4
Section Summary

A metallic bond forms when metal cations attract freely moving, delocalized valence electrons.

The electron sea model explains the physical properties of metallic solids.

Metal alloys are formed when a metal is mixed with one or more other elements.

can you2
Can you…

Describe a metallic bond

Relate the electron sea model the physical properties of metals

Define alloys and categorize them into two basic types.

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