1. Periodic Trends Analysis Cont.

2. Evaluation/ Assessment
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

3. 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

4. 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?

5. 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.

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

7. Agenda Warm – Up Finish Periodic Trends Graphing Activity Discussion
Periodic Trends Notes
Periodicity Practice Worksheet
Exit ticket

8. Periodic Trends Graphing Activity

9. Atomic Radius
Distance from the center of an atom to the outermost edge of the electron cloud

10. Electronegativity
The ability to attract electrons in a chemical bond

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

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

13. Periodic Trends Notes

14. 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

15. 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

16. 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

17. Atomic Radius

18. 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

19. Ionization Energy

20. Ionization Energy
First Ionization Energy – energy needed to remove the first electron
Removing a second electron requires more energy

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

22. Electronegativity

23. 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

24. Ionic Size

25. 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

26. Electron Affinity
The more negative the electron affinity, the greater attraction for an added electron
Generally, nonmetals have greater electron affinity than metals

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

28. Exit Ticket
Explain the patterns in the trends down a family and across a period for:
Atomic radius
Electronegativity
Ionization energy