Chapter 10

Ionization Energy

A good number of transition metal elements possess an ability to have more than one positive ion. (Remember +2 is the most common oxidation number for metal ions)

Mn +2Mn Mn +4 Mn +6

Mn +7

Demonstration

Mn

a

Demonstration

Mn

a

Ionization Energy

• Ionization energy is the energy needed to remove an electron from an atom or ion.

First Ionization Energy

• First Ionization energy is the energy needed to remove the first electron from an atom.

First Ionization Energy

• Francium has the lowest first ionization energy.

How would you relate ionization energy to atomic size and effective

nuclear charge?

How would you relate ionization energy to atomic size and effective

nuclear charge?

• Large atoms with low effective nuclear charge have low ionization energies.

• Small atoms with high effective nuclear charge have high ionization energies.

Ionization Energy

First Ionization energy is the energy needed to remove the first electron from an atom.

Multiple Ionization Energies

Second Ionization energy is the energy needed to remove the second electron from an atom.

Multiple Ionization Energies

• How many ionization energies does carbon have?

Ionization Energies in kJ/mol

1 2 3 4 5 6 7

H 1312

He 2372 5250

Li 520 7297 11810

Be 899 1757 14845 21000

B 800 2426 3659 25020 32820

C 1086 2352 4619 6221 37820 47260

N 1402 2855 4576 7473 9442 53250 64340

Multiple Ionization Energies

• What happens to carbon’s size and effective nuclear charge as you remove electrons?

Teacher Demonstrations

• Sodium and water

• Potassium and water

Homework

• Ionization Energy Worksheet

• Do the Lab Summary for “Reactivity and the Periodic Table”