Ionization Energy October 5*4*1, * 10 3  Objective:  SWBAT explain trends in ionization energy across a periodic table  Catalyst:  What is the octet rule?  How many electrons will oxygen want to gain or lose to become a full octet?  What do you think would happen if Magnesium lost 3 electrons?

Agenda  Catalyst  Characteristics of Ionic Bonds  Figure it out yourself: Ionization energy  Practice, Practice, Practice  Exit Question

Atoms  Some atoms are desperate to gain or lose electrons to fill out their octet!  But where do they get these electrons?  The electron store? NO!  Outer space? NO!  Walmart? NO!  Other elements? YESSSSSSSSSS!!!!!!

Bonding  Key Point #1:  There are two main ways an atom gains or loses electrons: By completely transferring them to another element- Ionic Bond By sharing electrons with another element- Covalent Bond Ionic Bonds this week! Covalent bonds next week!

Ionic Bonds  When atoms come together through an ionic bond, it is called an ionic compound  They transfer electrons so everyone is happy!

Example of an Ionic Bond Chlorine steals one of sodium ’ s electrons

Characteristics of Ionic Substances  Electrons are transferred  Bonds between metals and non- metals KNO 2

More Characteristics of Ionic Substances  They make crystals!  High melting points  Good conductors of electricity when dissolved

Who can think of practical applications? Why is tap water more conductive than distilled water?

Who can think of practical applications? What is an electrolyte? Do you think that Gatorade would conduct electricity? electricity

Even more practical!  Humans’ skin is slightly ionic because of sweat that is produced…  Let’s see how one innovator took this fact to make a really cool invention…

Ionization Energy  Key Point #2:  Ionization energy is the amount of energy it takes to remove the outermost electron from an atom.  REMEMBER THE OCTET RULE!

1st IONIZATION ENERGY the energy required to remove the first electron from an atom

The 1 st ionization energy DECREASES as you go down a family

The 1 st ionization energy INCREASES across a period (more p + have more pull on e - )

Multiple Ionization Energies  You are going to figure out a trend in multiple ionization energies.  This material is at a college level… but shucks, you guys are ready.  First things first, draw a Bohr model for four elements: Li, Be, B, C.

Electronegativity/Ionization Energy IE 1 – 1 st Ionization energy IE 2 – 2 nd Ionization energy IE 3 – 3 rd Ion. en. Etc…

Ionization Energy Can you figure out why there is such an increase in the red numbers? Use your BOHR models!! (10 mins) LiBe B C IE IE 2 7, IE 3 14, IE 4 25, IE 5 37,830

Do you get it?  Why does it take more energy to remove Lithium’s 2 nd electron than it takes to remove Carbon’s 4 th electron?  Hint: Start with a Bohr model

Ionization Energies  Key Point #3:  Breaking a full valence shell will cause a dramatic increase in ionization energy.

Guided Practice (GP)  Which has a higher 3 rd ionization energy  Silicon or Magnesium?

Guided Practice (GP)  What has a higher 1 st ionization energy?  Sodium or Neon?

Guided Practice (GP)  What has a higher 2 nd ionization energy?  Boron or Sodium?

Guided Practice (GP)  What has a higher 4 th ionization energy?  Nitrogen or Fluorine?

Guided Practice (GP)  What has a higher 2 nd ionization energy?  Aluminum or Silicon?

Independent Practice (IP) What you do not finish is HW!

GEE Test Practice:

Exit Question  Which element has a bigger 3 rd ionization energy: Boron or Calcium?  Which element has the larger 1 st ionization energy: Fluorine or Magnesium?