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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+