Periodic Trends Analysis Cont.

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Periodic Trends Analysis Cont.
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• Objective
• Today I will be able to
• Analyze the trends of ionization energy,
  electronegativity and atomic radius by completing
  a graphing activity.
• Explain the trends of ionic radius and electron
  affinity.
• 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

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Lesson Sequence

• Warm Up
• Explain Introduction to the periodic table notes
  and video clips
• Explore graphing the data of periodic trends
• Informal assessment listening to student ideas
  about trends as they graph data
• Elaborate identify the trends in noble gases and
  across periods
• Informal assessment as students predict trends

• Explain Review the explanation for the trends of
  radius, ionization energy and electronegativity
• Explain Trends of ionic radius, electron
  affinity, and reactivity
• Elaborate Periodicity Practice
• Formal assessment
• Evaluate Exit ticket
• Formal assessment

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Warm - Up

• What is atomic radius?
• 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?

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Objective

• Today I will be able to
• Analyze the trends of ionization energy,
  electronegativity and atomic radius by completing
  a graphing activity.
• Explain the trends of ionic radius and electron
  affinity.

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Homework

• STEM Fair
• Final Research Paper due Monday December 17
• In Class Presentations Wednesday January 23
• Periodicity Practice

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Agenda

• Warm Up
• Finish Periodic Trends Graphing Activity
• Discussion
• Periodic Trends Notes
• Periodicity Practice Worksheet
• Exit ticket

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Periodic Trends Graphing Activity
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Atomic Radius

• Distance from the center of an atom to the
  outermost edge of the electron cloud

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Electronegativity

• The ability to attract electrons in a chemical
  bond

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Ionization Energy

• Energy needed to remove an electron from an atom
• High ionization energy means atoms hold their
  electrons very tightly

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Graph Data

• Construct 3 graphs for ionization energy,
  electronegativity and atomic radius. Respond to
  questions on the Worksheet.

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Periodic Trends Notes
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Atomic Radius

• Distance from the center of an atom to the
  outermost edge of the electron cloud
• Increases down a group, decreases moving from
  left to right across a period

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Atomic Radius

• As you move down a group, the number of outermost
  electrons increases
• As you move across a period, more protons exert a
  pull on the electrons pulling them tighter
• Transition metals do not change size much based
  on electron to electron repulsion in the d
  sublevel

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Atomic Radius

• As you add an electron, there is an additional
  proton that creates a force between the nucleus
  and electrons that is stronger than the repulsion
  between electrons, and therefore the atomic
  radius decreases with additional protons across a
  period

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Atomic Radius
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Ionization Energy

• Energy needed to remove an electron from an atom
• High ionization energy means atoms hold their
  electrons very tightly (noble gases)
• Exactly opposite to atomic radius trend! Smaller
  atoms can hold their electrons more tightly
  together

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Ionization Energy
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Ionization Energy

• First Ionization Energy energy needed to remove
  the first electron
• Removing a second electron requires more energy

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Electronegativity

• The ability to attract electrons in a chemical
  bond
• Increases across a period and decreases down a
  group

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Electronegativity
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Ionic Size

• Actual size of the atom
• Ionic size is based on proton to electron ratios
• When atoms lose electrons they get smaller, when
  they gain electrons they get larger

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Ionic Size
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Electron Affinity

• The energy change that occurs when an atom gains
  an extra electron
• Negative electron affinities indicate that the
  elements do not require energy to gain an
  electron, instead they release energy

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Electron Affinity

• The more negative the electron affinity, the
  greater attraction for an added electron
• Generally, nonmetals have greater electron
  affinity than metals

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Periodicity Practice

• Complete the practice worksheet at your seat. We
  will review selected answers as a class and then
  hand the assignment in.

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Exit Ticket

• Explain the patterns in the trends down a family
  and across a period for
• Atomic radius
• Electronegativity
• Ionization energy