Periodic Trends Summary, Periodicity Practice Periodic Trends Activity 3 Periodic Trends Summary, Periodicity Practice

Explain why the periodic trends occur on the nuclear level Objectives Today I will be able to: Analyze how the trends of atomic radius, ionization energy and electronegativity change across a period and down a family Explain why the periodic trends occur on the nuclear level Compare the atomic radius, ionization energy and electronegativity of 2 or more elements Informal assessment: monitoring student questions and interactions as we complete the practice Formal assessment: analyzing the students interpretations of the trends, practice and exit ticket Common Core Connection Model with mathematics Look for and express regularity in repeated reasoning

Lesson Sequence Evaluate: Warm – Up Elaborate: Finish Data Analysis Explore: Why do the trends occur discussion Explain: Why do the trends occur notes Elaborate: Periodicity Practice Worksheet Evaluate: Exit Ticket

Warm - Up Last class we predicted that N would have a larger radius than C. This is incorrect based on the data we collected. Why would N have a smaller radius that C? Last class we predicted that Cl would be larger than F. This prediction was correct. Why is the radius of Cl larger?

Objective Today I will be able to: Analyze how the trends of atomic radius, ionization energy and electronegativity change across a period and down a family Explain why the periodic trends occur on the nuclear level Compare the atomic radius, ionization energy and electronegativity of 2 or more elements

Homework Finish Periodicity WS

Agenda Warm-Up Finish Data Analysis Why do the trends occur discussion and notes Periodicity Practice Exit Ticket

Take out your graphs and the data sheet from last class Take out your graphs and the data sheet from last class. We will begin by interpreting the trends of ionization energy and electronegativity from the data we graphed Finish Data Analysis

Why do the Trends Occur?

Group Discussion: Draw this table in your notes and discuss with your table (10 minutes) Trend How it changes Why the change occurs Atomic Radius Across a period Down a family Ionization Energy Electronegativity

Atomic Radius

Atomic Radius… Decreases across a period Why? Increases down a family More protons in the nucleus, pulling the electron cloud closer to the nucleus Increases down a family More energy levels for the electrons to fill

Ionization Energy

Ionization Energy Increases across a period Why? A greater number of valence electrons makes it more difficult to remove an electron Decreases down a family The electrons are farther away from the nucleus. They are less attracted to the atom making them easier to remove

Electronegativity

Electronegativity

Electronegativity

Electronegativity Increases across a period Why? Atoms are closer to reaching stability so they want to attract electrons Decreases down a family The electrons are farther away from the nucleus in higher energy levels. They are not attracted to the nucleus as easily

Periodicity Practice Worksheet Complete the worksheet using your notes. Ask Ms. Ose for help if you have questions we will review selected problems. Periodicity Practice Worksheet

Exit Ticket For the following set of elements: Ba Mg O 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