Ions + Ionic Bonding

Chapter 15

Bonds in Proportion

Valence electrons Valence e- the

number of e- in the highest energy level

How do you determine valence e-?

Quiz yourself How many valence e-

for Li, Na, K, Rb, Cs

Al Si P S Cl

Octet Rule Atoms want a complete (full) outer

energy level For most that means 8 electrons Exceptions to the rule?

H, He, Li, Be, B – they want 2 Elements will mimic the electron

configuration of a noble gas

Ions An ion is an atom with a charge

Cation is a positive ion (loses e-) Anion is a negative ion (gains electrons)

The common charge of an atom is called its OXIDATION Number

Oxidation Numbers What is the oxidation number of Na?

+1 What is the oxidation number of F

-1 What is the oxidation number for Mg

+2 What is the oxidation number for Te

-2

Electrostatic Attraction A reactive element gains or loses e-

in the presence of another element that will do the opposite

(OPPOSITES ATTRACT)

Ionic Bonds

How and why does sodium bond with chlorine?

1e-

http://www.youtube.com/watch?v=WEUXVQ95Rvk&feature=related&safety_mode=true&persist_safety_mode=1

Click for Fe + SClick for Na +

Clvideo

More than just diatomicsCan you figure these out?

Mg + F Mg2+ + F- MgF2

Al + Cl Al+3 + Cl- AlCl3

Swap and Drop Write the oxidation number

Swap the positive and negative ox # and make it the subscript of the other element

Ex: Mg2+ + Cl-1 → MgCl2

Try theseK + O K2OAl + O Al2O3

Mg + N Mg3N2

Polyatomic IonsYou should know these names of polyatomic

ions

NO3- nitrate

OH- hydroxideClO3

- chlorateSO4

2- sulfatePO4

3- phosphate

Try TheseMg2+ + NO3

-

Mg(NO3)2

K+ + OH-

KOHCa2+ + PO4

3-

Ca3(PO4)2