1. Ionic and Covalent bonding
David A. Katz
Pima Community College
Tucson, AZ

3. Ionic Bonding Between a metal with low ionization energy
( little energy required to remove an electron)
and a non-metal with high electronegativity and electron affinity
( wants to grab an electron towards it)

7. Formation of NaCl

8. Lewis Structures for Ionic CompoundsBa • O •• •• O Ba 2+ 2-
BaO Mg • Cl •• •• Cl Mg 2+ - 2
MgCl2
Binary ionic compounds.
Note the types of arrows used to move electrons – fishhooks for single e-.
Write the Lewis symbol for each atom Determine how many e- each atom must gain or lose.
Use multiples of one or both ions to balance the number of electrons.

10. Properties of Ionic Compounds
Held together by strong electrostatic forces
Opposite charges attract
High melting points and boiling points
Regular structures – giant ionic lattices
When melted or dissolved ionic compounds conduct electricity

11. Dissolving in Water

12. conductivity

13. Covalent Bond
Between two elements with high ionization energy ( do not give up electrons easily) and high electronegativity ( try to grab the electron to each of them)
Here neither atom is willing to give up its electron
Instead the nuclei share the electrons between them

16. Lewis Structures
Lewis structures are representations of molecules showing all electrons, bonding and non-bonding
Example :
Li2 O

17. Lewis structures F2
C2H6

18. Multiple Covalent bonds
More than one pair of electrons can be shared between the same atoms
O2 N2

20. Properties of Covalent Molecules
Contain non-metals
Weak bonds
Valence electrons are shared between atoms
Polar molecules dissolve in polar solvents
Volatile
Low melting and boiling points
Insoluble in water
Non polar compounds do not conduct electricity; polar compounds can conduct small amounts of electricity