Post on 09-Aug-2020
transcript
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