Catalyst1. List an element from the following groups: alkali, alkaline earth metal, transition metal, halogen, and Noble gas.2. Why do different groups have different properties?3. Label as metal, non-metal, or semimetal: sodium, silicon, neon, and cobalt.

End

Lecture 1.6 – 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. Furthermore, I can explain how this trend changes as you move throughout the Periodic Table.

What is ionization energy?

I. Nuclear Attraction• The negatively charged electrons are

attracted towards the positively charged 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.

• IE decreases because it requires less energy to remove an electron due to shielding of orbits.

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 attraction for electrons.

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 Ticket

1. Arsenic is a metal, non-metal, or semimetal?2. A student states that fluorine is a metal that

is part of the noble gas family. What is wrong with this statement?

3. Order these from smallest to largest ionization energy: O, F, N

4. Why does IE decrease as you go down a group?

Closing Time• UNIT 1 TEST NEXT TUESDAY/WEDNESDAY!