1. Catalyst 9/4/13 On your Catalyst Sheet, please answer the following questions: 1. What happens to ionization energy as you go down a group? 2. Sort from lowest to highest IE: P, S, Mg 3. Sort from highest to lowest IE: Kr, He, Ne

2. Announcement #1 TURN IN YOUR COIN DENSITY LAB REPORT (if you haven’t already) Deadline for credit: Monday 9/9 (Periods 1/3/5); Tuesday 9/10 (Periods 2/4)

3. Announcement #2 UNIT 1 EXAM NEXT MONDAY (9/9) OR TUESDAY (9/10) (WRITE DOWN IN AGENDA) COVERS EVERY LEARNING TARGET IN THIS UNIT (1.1 – 1.9) – 1.1 Intro to the Atom – 1.2 Development of Atomic Theory – 1.3 Periodic Table – 1.4 Bohr Models – 1.5 Element Families – 1.6 Metals/Semimetals/Nonmetals – 1.7, 1.8, 1.9 Ionization Energy/Electronegativity/Atomic Radius

4. Homework Answers

5. Steal Mr. Pan’s Wallet!

6. Lecture 1.7 – Ionization Energy

7. Today’s Learning Target 1.7 – I can define ionization energy and explain how it relates to the charge of the nucleus and the electron. I can explain how this trend changes as you move throughout the Periodic Table.

8. What is ionization energy?

9. I. Nuclear Attraction Negative electrons are attracted towards the positive nucleus. Negative electrons are attracted towards the positive nucleus.

11. II. Ionization Energy Ionization energy is the energy that is required to remove an electron. Ionization energy is the energy that is required to remove an electron.

12. What are the trends for ionization energy?

13. I. IE Trends As you move down a group, the IE decreases. As you move down a group, the IE decreases. As you move across a period, the IE increases. As you move across a period, the IE increases.

16. Why do these trends exist?

17. I. Why IE Decreases Down a Group As you go down a group more orbits are added. As you go down a group more orbits are added. Nuclear attraction becomes weaker due to more orbits shielding the nucleus Nuclear attraction becomes weaker due to more orbits shielding the nucleus IE decreases because less energy is required to remove an outer electron. IE decreases because less energy is required to remove an outer electron.

19. Electron Shielding: Explained with a Lamp and Socks

20. II. Why IE Increases Across a Period As you move across a period you add more protons and electrons within the same orbit. As you move across a period you add more protons and electrons within the same orbit. The larger amount of protons show an increased nuclear attraction for electrons. The larger amount of protons show an increased nuclear attraction for electrons. IE increases because more energy is required to remove an electron IE increases because more energy is required to remove an electron

22. Class Example Order the elements from smallest to largest IE: potassium, cesium, lithium.

23. Table Talk Order the elements from largest to smallest IE: Fluorine, Carbon, Oxygen.

24. Stop and Jot Order the elements from smallest to largest IE: phosphorus, arsenic, nitrogen.

25. SUMMARIZE

26. White Board Races

27. 1.Order the following elements from smallest IE to largest IE: Arsenic, Gallium, Germanium. 2.Which element has a larger IE: fluorine or selenium? 3.Which element has a smaller IE: Cesium or Astatine? 4.Why does germanium have a higher ionization energy than lead? 5.Why does silicon have a lower ionization energy than phosphorus?

28. Exit Slip 1.Order these from smallest to largest ionization energy: O, F, N 2.Order these from smallest to largest ionization energy: Na, Li, Cs 3.In complete sentences explain why IE decreases as you go down a group.

29. Closing Time UNIT 1 EXAM NEXT MONDAY/TUESDAY