Ionic Trends1-3-11

1. Cornell Notes2. Examples3. Practice

What have we learned so far?

Does this look familiar?

Octet RuleAtoms lose, gain or share valence electrons in

order to acquire the stable electron configuration of a noble gas (8 valence e-)

Na Cl+ Na+ Cl+-

Cation Anion

Trends in Ion Formation

Groups 1 to 4 give their valence electrons away1

2 13 14 Li Li+

Mg Mg2+

B B3+

Trends in Ion Formation

Groups 5 to 7 take electrons

5 67 P P3-

O O2-

F F-

IonAn atom or group of atoms with a positive or negative charge

To create an ion: Gain an electron (to become negative) Lose an electron (to become positive)

Example: Lithium can lose one electron to become

Li+

+0

+0

-

-

Ionization EnergyThe energy needed to remove an electron from a gaseous atom.

Higher energy = atom holds on to electrons more tightly

Affected by nuclear charge (#of protons in nucleus) and number of energy levels

+0

+0

-

-

Ionization EnergyIncreases across a periodIncreases up a group

ExampleWhich has the larger ionization energy:

Lead (Pb) or Sulfur (S)?

SULFUR

Ionic RadiusThe size of an ionPositive ions are smaller (lose electrons)

Negative ions are larger (gain electrons)

Ionic RadiusPositive Ions Negative Ions

Generally Increase

ExampleWhich element has the larger ionic radius:Cs+ or Cl-?

POSITIVE

NEGATIVE

Cl-

PracticeOn the back of your notes…

Answer the questions section by sectionHave your answers checked by the teacher

AFTER EACH SECTION IS COMPLETED If your answers are correct, move on to the next

section

Make sure you get your work checked off after each section – it will only be graded DURING CLASS!

ExampleWhich element has the larger ionic radius:

Cs+ or Mg2+

Positive Ions

Generally Increase Cs+