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, Mg3. Sort from highest to lowest IE: Kr, He, Ne

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)

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

Homework Answers

Steal Mr. Pan’s Wallet!

Lecture 1.7 – Ionization Energy

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.

What is ionization energy?

I. Nuclear Attraction• Negative electrons are attracted

towards the positive nucleus.

II. Ionization Energy

• Ionization energy is the energy that is required to remove an electron.

What are the trends for ionization energy?

I. IE Trends

• As you move down a group, the IE decreases.

• As you move across a period, the IE increases.

Why do these trends exist?

I. Why IE Decreases Down a Group

• As you go down a group more orbits are added.

• Nuclear attraction becomes weaker due to more orbits shielding the nucleus

• IE decreases because less energy is required to remove an outer electron.

Electron Shielding: Explained with a Lamp and Socks

II. Why IE Increases Across a Period

• 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.

• IE increases because more energy is required to remove an electron

Class Example

• Order the elements from smallest to largest IE: potassium, cesium, lithium.

Table Talk

• Order the elements from largest to smallest IE: Fluorine, Carbon, Oxygen.

Stop and Jot

• Order the elements from smallest to largest IE: phosphorus, arsenic, nitrogen.

SUMMARIZE

White Board Races

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?

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.

Closing Time• UNIT 1 EXAM NEXT

MONDAY/TUESDAY