2.  Objectives  Today I will be able to:  Describe how the trends of ionic radius and electron affinity change across a period and down a family  Compare the atomic radius, ionization energy, electronegativity, ionic radius and electron affinity of 2 or more elements  Informal assessment: monitoring student questions and interactions as we complete the practice  Formal assessment: analyzing the students practice and exit ticket  Common Core Connection  Model with mathematics  Look for and express regularity in repeated reasoning

3.  Evaluate: Warm-up  Explain: Electron Affinity/Ionic Radius Notes  Elaborate: Periodic Trends Practice  Evaluate: Exit Ticket

4.  For the following set of elements: CaSrBaRa  Circle the element that has the smallest atomic radius  Underline the element with the smallest ionization energy  Box the element with the greatest electronegativity value

5.  Today I will be able to:  Describe how the trends of ionic radius and electron affinity change across a period and down a family  Compare the atomic radius, ionization energy, electronegativity, ionic radius and electron affinity of 2 or more elements

6.  Finish the practice from class  Periodic Table Quiz – Thursday, November 20

7.  Warm-Up  Ionic Radius/Electron Affinity Notes  Periodicity Review  Periodic Trends Practice  Exit Ticket

9.  When an atom gains or loses electrons the size of the radii change  Ionic radius is different for cations and anions

10.  Example: Mg 2+  Two electrons are removed  The radius gets smaller  Why?  Less repulsion between the electrons and the same number of protons in the nucleus pulls the electrons closer

11.  Example: Cl 1-  One electron is added  The radius gets larger  Why?  More repulsion between the electrons and the same number of protons in the nucleus spreads the electrons farther apart

12.  Energy change that occurs when an atom gains an electron  Across a period  Energy becomes more negative (more energy is released)  Down a family  Energy becomes less negative down a family (less energy is released0

14.  Can there be more than one? Why so?  What we have talked about so far has been 1 st ionization energy  There are actually as many ionization energies as there are electrons for an element !

16. Complete the practice at your desk. We will review selected responses as a class. Please ask Mr. Klotz for help If you have questions.

17.  Which of the following ions would have a smaller ionic radius? Explain why it would be smaller F 1- Na 1+