Trends Review, History of the
Periodic Table, Oxidation Numbers
• Objective
– Today I will be able to:
• Apply the trends of ionization energy, electronegativity and atomic
radius to problem solving.
• Explain the history of the periodic table.
• Identify the oxidation numbers for the families of elements on the
periodic table.
• Evaluation/ Assessment
– Informal assessment – Listening to group interactions and
discussions as they complete the analyzing the periodic trends
graphing activity
– Formal Assessment – Analyzing student responses to the exit
ticket, graphs and periodicity practice
• Common Core Connection
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Build Strong Content Knowledge
Value Evidence
Reason abstractly and quantitatively
Look for and make use of structure
Lesson Sequence
• Warm – Up
• Evaluate: Review
Chapter 5 worksheet
• Informal assessment
• Elaborate: Periodicity
Practice
– Formal assessment
• Explain: history of the
periodic table and
oxidation numbers
• Elaborate: Practice and
Exam Review
– Informal Assessment
• Evaluate: Exit ticket
• Formal assessment
Warm - Up
• What is ionization energy?
– How does it change down a family?
• Why does this trend occur?
– How does atomic radius change across a period?
• Why does this trend occur?
• How does an atomic radius compare to an
ionic radius?
Objective
• Today I will be able to:
• Apply the trends of ionization energy,
electronegativity and atomic radius to problem
solving.
• Explain the history of the periodic table.
• Identify the oxidation numbers for the families of
elements on the periodic table.
Homework
• Periodic Table (mini-exam) on Thursday and
Friday next week
• STEM Fair
– Final Research Paper due Monday December 17
– In Class Presentations Wednesday January 23
Agenda
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Warm – Up
Study guide
Review Homework
Periodicity Practice Worksheet
History of the Periodic Table Notes
Oxidation Number Notes
Exam Review
Exit ticket
Review HW – Chapter 5
Worksheet
Discuss answers to selected problems
and then turn in
Periodicity Practice
Complete Worksheet and Review as a
class
History of the Periodic Table and
Oxidation Number Notes
Johann Dobereiner (1829)
• Law of Triads - in triads of elements the
middle element has properties that are an
average of the other two members when
ordered by the atomic weight
• Example - halogen triad composed of chlorine,
bromine, and iodine
John Newlands (1864)
• Law of Octaves - states that any given element
will exhibit analogous behavior to the eighth
element following it in the periodic table
Dmitri Mendeleev (1871)
• Developed the first Periodic Table
• He arranged his table so that elements
in the same column (groups) have
similar properties; increasing atomic
mass
Dmitri Mendeleev (1871)
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Broke the trend of arranging elements solely by
their atomic mass
Wanted to keep elements with similar properties in
the same columns
Left gaps in his early tables; predicted elements
that had not been discovered would fill in those
gaps
- Ekasilicon  Germanium
- Germanium was discovered in 1886
Dmitri Mendeleev (1871)
Henry Moseley (1913)
• Found a relationship between an element’s X-ray
wavelength and it’s atomic number (number of
protons)
• Periodic Law - when elements are arranged in
order of increasing atomic number, their physical
and chemical properties show a periodic
(repeating) pattern
• The periodic law is the basis for arranging
elements in the periodic table
Glenn Seaborg
• He reconfigured the periodic table by placing
the actinide series below the lanthanide series
• Awarded a Nobel Prize in 1951
• Element 106, Seaborgium (Sg), is named in his
honor
Oxidation Numbers
Oxidation Numbers
• Remember, most atoms strive to have
eight valence electrons (some are
satisfied with only two)
• Atoms will form various bonds by
gaining, losing, or sharing electrons, in
order to satisfy the Octet Rule
Oxidation Numbers
• An atom’s electron configuration is used to
determine how many electrons need to be
gained, lost, or shared
• Example – Na (11 electrons)
• 1s2 2s2 2p6 3s1 – 1 valence electron
• In order for Na to have eight valence
electrons, would it be easier for it to gain 7
electrons, or lose 1?
• Losing 1 is easier
Oxidation Numbers
• When Na loses an electron it becomes an Na+1
ion
• 1s2 2s2 2p6 3s1 becomes…
• 1s2 2s2 2p6 – 8 valence electrons
• Na carries a +1 charge because it has lost an
electron, and it now has more positively
charged protons than negatively charged
electrons
Oxidation Numbers
• Another Example – Fluorine (9 electrons)
• 1s2 2s2 2p5 – 7 valence electrons
• In order for F to have eight valence electrons,
would it be easier for it to gain 1 electron, or
lose 7?
• Gaining 1 is easier
Oxidation Numbers
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When F gains an electron it becomes an F-1 ion
1s2 2s2 2p5 becomes…
1s2 2s2 2p6 – 8 valence electrons
F carries a -1 charge because it has gained an
electron, and it now has more negatively
charged electrons than positively charged
protons
Oxidation Numbers
• There is a fairly consistent pattern to oxidation
numbers with families
• Transition Metals and Inner Transition Metals
usually have a varying number of valence
electrons
• Some don’t – Zn+2, Cd+2, Sc+2, Ag+1
Exam Review
Complete with the people in your
row. If you have questions please ask
Ms. Ose
Exit Ticket
• Which element is more likely to have a higher
(more negative) electron affinity, Aluminum or
Sulfur?
• List the oxidation number for the following
families
– Alkali metals
– Alkaline earth metals
– Halogens
– Noble Gases