1. Chem-To-Go Lesson 12 Unit 3 IONIZATION ENERGY & ELECTRONEGATIVITY

2. 1 ST IONIZATION ENERGY Definition: the energy required to remove a first electron from an atom

3. 1 ST IONIZATION ENERGY

4. Period trend: [row pattern]; ionization energy INCREASES from left to right across a row Group trend: [column pattern]; ionization energy INCREASES from bottom to top of a column WHY? The energy needed to remove an electron increases as the nucleus becomes more strongly positive and the electrons are drawn in closer to it. The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels. PERIOD TREND GROUP TREND

5. 1 ST IONIZATION ENERGY SHIELDING EFFECT OF CORE ELECTRONS The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

6. 1 ST IONIZATION ENERGY Memory Tool SAMPLE MULTIPLE CHOICE: 1. Which of the following atoms will has the smallest ionization energy? a. Tinb. Strontium c. Selenium d. Arsenic Use a periodic table! Find all of the elements. Apply the trend.

7. 1 ST IONIZATION ENERGY Memory Tool SAMPLE MULTIPLE CHOICE: 2. Which of the following atoms has a larger ionization energy than calcium? a.Aluminum b. Copper c. Potassiumd. None Use a periodic table! Find all of the elements. Apply the trend.

8. ELECTRONEGATIVITY Definition: the ability of an atom in a chemical bond to draw the bonding electrons closer to itself

9. ELECTRONEGATIVITY Notice that the noble gases are NOT in the image. Since they don’t form bonds, they have no electronegativity values.

10. ELECTRONEGATIVITY Period trend: [row pattern]; electronegativity INCREASES from left to right across a row Group trend: [column pattern]; electronegativity INCREASES from bottom to top of a column WHY? The larger and more positive nuclei on the right side of the table are more likely to attract the bonding electrons An unshielded nucleus is better at attracting bonding electrons. Fewer energy levels means more electronegativity. PERIOD TREND GROUP TREND

11. ELECTRONEGATIVITY Memory Tool SAMPLE MULTIPLE CHOICE: 1. Which of the following atoms will has the highest electronegativity? a. Tinb. Chlorine c. Neon d. Arsenic Use a periodic table! Find all of the elements. Apply the trend.

12. ELECTRONEGATIVITY Memory Tool SAMPLE MULTIPLE CHOICE: 2. Which of the following atoms will has a higher electronegativity than P? a.Oxygen b. Fluorine c. Heliumd. None Use a periodic table! Find all of the elements. Apply the trend.