Ionic Bonds

Characteristics of an

Ionic Bond

Characteristics

High melting and boiling points

Tend to be soluble in water

Can conduct electricity in the molten

state

Crystallize as sharply defined particles

Generally form between metals and

nonmetals.

Ionic Bonding

Terms and why do

they bond.

Bonding Order

The first atoms listed in the formula will have a positive charge (cations).

The last groups of atoms listed will have a negative charge (anions).

NaCl

Na is the cation

Cl is the anion

BeCl2

Be is the cation

Cl is the anion

NH4NO3

NH4 is the cation - it is a polyatomic ion

NO3 is the anion – it is a polyatomic ion

Na2SO4

Na is the cation

SO4 is the anion

Valence Review

For the main group elements,:

1 valence for the alkali family

2 valence for the alkaline earth

3 for boron family

4 for carbon family

5 for nitrogen family

6 for oxygen family

7 for halogen family

8 for noble gases, but He (has 2)

Drawing Lewis Dot for Elements

Symbol of element is in the center

Dots are distributed around the symbol

representing the total valence electrons

“s” electrons are paired first

“p” electrons are distributed around the

remaining three sides individually before

pairing occurs

Atoms bond together to achieve noble gas configurations.

Energy must be put into the system to form a bond.

We have to provide some push (energy).

Bonding Steps

1. A transfer of electrons occurs

2. An electrostatic attraction

Examples

Li and Cl

Li and O

Metallic Bonding

Metallic Bonding

When two or more metals come together to form a bond.

These types of bonds are weaker then ionic bonds.

They are weaker because electrons are not truly transferred to one atom.

Electrons are delocalized over all the atoms, creating a bond.

Metallic or Ionic

PbO

Ionic

LiNa

Metallic

AuAu

Metallic

NaFe

metallic