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

Evaluate: Warm-up Explain: Electron Affinity/Ionic Radius

Notes Elaborate: Periodic Trends Practice Evaluate: Exit Ticket

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

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

Finish the practice from class Periodic Table Quiz – Wednesday,

November 19

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

When an atom gains or loses electrons the size of the radii change

Ionic radius is different for cations and anions

Example: Mg2+

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

Example: Cl1-

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

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

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

Which of the following ions would have a smaller ionic radius? Explain why it would be smaller

F1- Na1+