Chapter 6
The Periodic Table and Periodic Law
National Standards for Chapter 5
–
–
–
–
–
–
–
–
–
–
–
–
–
UCP.1 Systems, order, and organization
UCP.2 Evidence, models, and explanation
UCP.5 Evolution and equilibrium
A.1 Abilities necessary to do scientific inquiry
A.2 Understandings about scientific inquiry
B.1 Structure of atoms
B.2 Structure and properties of matter
B.6 Interactions of energy and matter
E.1 Abilities of technological design
E.2 Understandings about science and technology
G.1 Science as a human endeavor
G.2 Nature of scientific knowledge
G.3 Historical perspectives
Vocabulary/Study Guide
• Define each term using the Glossary
• Either write on the handout, or use your own
paper
• This is due on Test Day (tentatively, Thursday,
November 21)
Section 1: Development of the
Modern Periodic Table
• National Standards:
–
–
–
–
–
–
–
–
–
–
–
UCP.1 Systems, order, and organization
UCP.2 Evidence, models, and explanation
UCP.5 Evolution and equilibrium
A.1 Abilities necessary to do scientific inquiry
A.2 Understandings about scientific inquiry
B.1 Structure of atoms
B.2 Structure and properties of matter
E.2 Understandings about science and technology
G.1 Science as a human endeavor
G.2 Nature of scientific knowledge
G.3 Historical perspectives
Objectives – Section 1
• Trace the development of the periodic table.
• Identify key features of the periodic table.
REVIEW VOCABULARY:
atomic number: the number of protons in an atom
• The periodic table evolved over time as
scientists discovered more useful ways to
compare and organize the elements.
New Vocabulary
periodic law
group
period
representative elements
transition elements
metal
alkali metals
alkaline earth metals
transition metal
inner transition metal
lanthanide series
actinide series
nonmetals
halogen
noble gas
metalloid
Lab: How Can You Recognize Trends?
• OBJECTIVE: To use the organization of
everyday items to help visualize the periodic
trends on the table of elements.
• PRE-LAB/PREDICTIONS:
– As you sort items, how does this help you to
predict physical and chemical properties?
• DATA:
– Create a periodic table of household fasteners in a
4x3 grid
Development of the Periodic Table
• In the 1700s, Lavoisier compiled a list of all the
known elements of the time.
Development of the Periodic Table
• The 1800s brought large amounts of
information and scientists needed a way to
organize knowledge about elements.
• John Newlands proposed an arrangement
where elements were ordered by increasing
atomic mass.
Development of the Periodic Table
• Newlands noticed
when the elements
were arranged by
increasing atomic
mass, their
properties repeated
every eighth
element.
Development of the Periodic Table
• Meyer and Mendeleev both demonstrated a
connection between atomic mass and elemental
properties.
• Moseley rearranged the table by increasing
atomic number, and resulted in a clear periodic
pattern.
• Periodic repetition of chemical and physical
properties of the elements when they are
arranged by increasing atomic number is called
periodic law.
Development of the Periodic Table
The Modern Periodic Table
• The modern periodic table contains boxes
which contain the element's name, symbol,
atomic number, and atomic mass.
The Modern Periodic Table
• Columns of elements are called groups.
• Rows of elements are called periods.
• Elements in groups 1,2, and 13-18 possess a
wide variety of chemical and physical
properties and are called the representative
elements.
• Elements in groups 3-12 are known as the
transition metals.
The Modern Periodic Table
• Elements are classified as metals, non-metals,
and metalloids.
• Metals are elements that are generally shiny
when smooth and clean, solid at room
temperature, and good conductors of heat and
electricity.
• Alkali metals are all the elements in group 1
except hydrogen, and are very reactive.
• Alkaline earth metals are in group 2, and are also
highly reactive.
The Modern Periodic Table
• The transition elements are divided into
transition metals and inner transition metals
• The two sets of inner transition metals are
called the lanthanide series and actinide series
and are located at the bottom of the periodic
table.
The Modern Periodic Table
• Non-metals are elements that are generally
gases or brittle, dull-looking solids, and poor
conductors of heat and electricity.
• Group 17 is composed of highly reactive
elements called halogens.
• Group 18 gases are extremely unreactive and
commonly called noble gases.
The Modern Periodic Table
• Metalloids have physical and chemical
properties of both metals and non-metals,
such as silicon and germanium.
Transparency 18: The Modern
Periodic Table
Lab: Analyze Trends, page 180
Lab: Investigate Descriptive Chemistry,
page 196
Homework, Section 1
•
•
•
•
SECTION 1 REVIEW, Page 181
Questions #1,2,4-7
Answer with complete sentences
Due tomorrow
Section 2: Classification of Elements
• National Standards:
– UCP.1 Systems, order, and organization
– UCP.2 Evidence, models, and explanation
– UCP.5 Evolution and equilibrium
– A.1 Abilities necessary to do scientific inquiry
– B.1 Structure of atoms
– B.2 Structure and properties of matter
Objectives – Section 2
• Explain why elements in the same group have similar
properties.
• Identify the four blocks of the periodic table based on
their electron configuration.
• Identify the relationships among a hydrogen atom's
energy levels, sublevels, and atomic orbitals.
Review Vocabulary:
valence electron: electron in an atom's outermost orbitals;
determines the chemical properties of an atom
Objectives – Section 2
Elements are organized into different blocks in
the periodic table according to their electron
configurations.
Organizing the Elements by Electron
Configuration
• Recall electrons in the highest principal energy
level are called valence electrons.
• All group 1 elements have one valence
electron.
Organizing the Elements by Electron
Configuration
• The energy level of an element’s valence
electrons indicates the period on the periodic
table in which it is found.
• The number of valence electrons for elements
in groups 13-18 is ten less than their group
number.
Organizing the Elements by Electron
Configuration
The s-, p-, d-, and f-Block Elements
• The shape of the periodic table becomes clear
if it is divided into blocks representing the
atom’s energy sublevel being filled with
valence electrons.
The s-, p-, d-, and f-Block Elements
• s-block elements consist of group 1 and 2, and
the element helium.
• Group 1 elements have a partially filled s
orbital with one electron.
• Group 2 elements have a completely filled s
orbital with two electrons.
The s-, p-, d-, and f-Block Elements
• After the s-orbital is filled, valence electrons
occupy the p-orbital.
• Groups 13-18 contain elements with
completely or partially filled p-orbitals.
The s-, p-, d-, and f-Block Elements
• The d-block contains the transition metals and
is the largest block.
• There are exceptions, but d-block elements
usually have filled outermost s-orbital, and
filled or partially filled d orbital.
• The five d-orbitals can hold 10 electrons, so
the d-block spans ten groups on the periodic
table.
The s-, p-, d-, and f-Block Elements
• The f-block contains the inner transition
metals.
• f-block elements have filled or partially filled
outermost s orbitals and filled or partially
filled 4f and 5f orbitals.
• The 7 f-orbitals hold 14 electrons, and the
inner transition metals span 14 groups.
Transparency 19: The s-,p-,d-, and fBlock Elements
Math Skills Transparency 6: Using the
Periodic Table
Homework, Section 2
•
•
•
•
•
•
PRACTICE PROBLEMS #8-10 on page 186
Write the problem, then the answer
SECTION 2 REVIEW, Page 186
Questions #11-15
Answer with complete sentences
Due tomorrow
Section 3: Electron Configuration
• National Standards:
–
–
–
–
–
–
–
–
–
–
–
–
UCP.1 Systems, order, and organization
UCP.2 Evidence, models, and explanation
UCP.5 Evolution and equilibrium
A.1 Abilities necessary to do scientific inquiry
A.2 Understandings about scientific inquiry
B.1 Structure of atoms
B.2 Structure and properties of matter
B.6 Interactions of energy and matter
E.1 Abilities of technological design
E.2 Understandings about science and technology
G.2 Nature of scientific knowledge
G.3 Historical perspectives
Objectives – Section 3
• Compare period and group trends of several
properties.
• Relate period and group trends in atomic radii to
electron configuration.
Review Vocabulary:
principal energy level: the major energy level of an atom
New Vocabulary
ion
ionization energy
octet rule
electronegativity
Trends among elements in the periodic table
include their size and their ability to lose or
attract electrons
Atomic Radius
• Atomic size is a periodic trend influenced by
electron configuration.
• For metals, atomic radius is half the distance
between adjacent nuclei in a crystal of the
element.
Atomic Radius
• For elements that occur as molecules, the
atomic radius is half the distance between
nuclei of identical atoms.
Atomic Radius
• There is a general decrease in atomic radius
from left to right, caused by increasing
positive charge in the nucleus.
• Valence electrons are not shielded from the
increasing nuclear charge because no
additional electrons come between the
nucleus and the valence electrons.
Atomic Radius
Atomic Radius
• Atomic radius generally increases as you move
down a group.
• The outermost orbital size increases down a
group, making the atom larger.
Atomic Radius
• Practice Problems #16-19, page 189
Ionic Radius
• An ion is an atom or bonded group of atoms
with a positive or negative charge.
• When atoms lose electrons and form
positively charged ions, they always become
smaller for two reasons:
1. The loss of a valence electron can leave an
empty outer orbital resulting in a small radius.
2. Electrostatic repulsion decreases allowing the
electrons to be pulled closer to the radius.
Ionic Radius
• When atoms gain electrons, they can become
larger, because the addition of an electron
increases electrostatic repulsion.
Ionic Radius
• The ionic radii of positive ions generally
decrease from left to right.
• The ionic radii of negative ions generally
decrease from left to right, beginning with
group 15 or 16.
Transparency 20: Atomic and Ionic
Radius
• Both positive and negative ions increase in
size moving down a group.
Ionization Energy
• Ionization energy is defined as the energy
required to remove an electron from a
gaseous atom.
• The energy required to remove the first
electron is called the first ionization energy.
Ionization Energy
Ionization Energy
• Removing the second electron requires more
energy, and is called the second ionization
energy.
• Each successive ionization requires more
energy, but it is not a steady increase.
Transparency 21: First Ionization and
Successive Ionization Energies
Ionization Energy
• The ionization at which the large increase in
energy occurs is related to the number of
valence electrons.
• First ionization energy increases from left to
right across a period.
• First ionization energy decreases down a
group because atomic size increases and less
energy is required to remove an electron
farther from the nucleus.
Ionization Energy
Lab: Organize Elements, page 193
Ionization Energy
• The octet rule states that atoms tend to gain,
lose or share electrons in order to acquire a
full set of eight valence electrons.
• The octet rule is useful for predicting what
types of ions an element is likely to form.
Ionization Energy
• The electronegativity of an element indicates
its relative ability to attract electrons in a
chemical bond.
• Electronegativity decreases down a group and
increases left to right across a period.
Ionization Energy
Lab: Properties of the Periodic Table
Lab: Periodic Trends in the Periodic
Table
Homework, Section 3
•
•
•
•
SECTION 3 REVIEW, Page 194
Questions #20-24
Answer with complete sentences
Due tomorrow
Key Concepts
• The elements were first organized by increasing atomic
mass, which led to inconsistencies. Later, they were
organized by increasing atomic number.
• The periodic law states that when the elements are
arranged by increasing atomic number, there is a
periodic repetition of their chemical and physical
properties.
• The periodic table organizes the elements into periods
(rows) and groups (columns); elements with similar
properties are in the same group.
Key Concepts
• Elements are classified as either metals,
nonmetals, or metalloids.
Key Concepts
• The periodic table has four blocks (s, p, d, f).
• Elements within a group have similar chemical
properties.
• The group number for elements in groups 1
and 2 equals the element’s number of valence
electrons.
• The energy level of an atom’s valence
electrons equals its period number.
Key Concepts
• Atomic and ionic radii decrease from left to right across
a period, and increase as you move down a group.
• Ionization energies generally increase from left to right
across a period, and decrease as you move down a
group.
• The octet rule states that atoms gain, lose, or share
electrons to acquire a full set of eight valence
electrons.
• Electronegativity generally increases from left to right
across a period, and decreases as you move down a
group.