IONIC RADIUS ELECTRON AFFINITY PERIODIC TRENDS PRACTICE Objectives

IONIC RADIUS, ELECTRON AFFINITY, PERIODIC TRENDS PRACTICE

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

LESSON SEQUENCE Evaluate: Warm-up Explain: Electron Affinity/Ionic Radius Notes Elaborate: Periodic Trends Practice Evaluate: Exit Ticket

WARM-UP For the following set of elements: 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

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

HOMEWORK Finish the practice from class Periodic Table Quiz – Wednesday, November 19

AGENDA Warm-Up Ionic Radius/Electron Affinity Notes Periodic Trends Practice Exit Ticket

IONIC RADIUS/ELECTRON AFFINITY NOTES

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

CATION 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

ANION 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

ELECTRON AFFINITY 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 released 0

ELECTRON AFFINITY

Complete the practice at your desk. We will review selected responses as a class. Please ask Ms. Ose for help If you have questions. PERIODIC TRENDS PRACTICE

EXIT TICKET Which of the following ions would have a smaller ionic radius? Explain why it would be smaller F 1 Na 1+