1. Focus on Covalent bonds types of bonds
Bonding
Focus on Covalent bonds
types of bonds

2. Octet Rule = atoms tend to gain, lose or share electrons so as to have 8 electrons, through the processes of bonding

3. Metallic Bonds Formed between atoms of metallic elements
Electron cloud around atoms
Strong bonds
Good conductors at all states, lustrous, very high melting points
Examples; Na, Fe, Al, Au, Co
Metals do not combine with metals. They form Alloys which is a solution of a metal in a metal.
Examples are steel, brass, bronze and pewter.

4. Metallic Bonds: Mellow dogs with plenty of bones to go around.

5. Review: Ionic Bonds
Ionic compounds result when metals react with nonmetals
Metals lose electrons to match the number of valence electrons of their nearest noble gas
Positive ions form when the number of electrons are less than the number of protons
Group 1 metals  ion 1+
Group 2 metals  ion 2+
Group 13 metals  ion 3+

6. Review: Ionic Bonds
Between atoms of metals and nonmetals with very different electronegativity
Bond formed by transfer of electrons
Produce charged ions all states. Conductors and have high melting point.
Examples; NaCl, CaCl2, K2O

8. Salt versus Molecules
A metal cation and nonmetal anion are joined together by an ionic bond called SALT
A group of atoms joined together by a covalent bond is called a MOLECULE
A Compound is a group of two or more elements bonded together (Ionic or Covalent).

9. Monatomic vs. Diatomic Molecules
Most molecules can be monatomic or diatomic
Diatomic Molecule is a molecule consisting of two atoms
There are 7 diatomic molecules (SUPER 7) – N2, O2, F2, Cl2, Br2, I2, H2
You can also remember them as: H2O2F2Br2I2N2Cl2

10. Properties of Molecular Compounds
Liquids or gases at room temperature
Lower Melting Points than Ionic Compounds (which means that they are weaker than ionic)

11. Ionic Compounds
Molecular Compounds
Crystal Lattice
Molecule
Types of Elements
Metal with non-metal or polyatomic ions
Non-metal with non-metal
Physical State
Solid
Solid, liquid or gas
Melting Point
High
> 300 C
Low
<300 C
Solubility in water
Generally high
Generally low
Electrical conductivity of solution
Good conductor
Poor to none

12. Covalent Bond
Between nonmetallic elements of similar electronegativity.
Formed by sharing electron pairs
Stable non-ionizing particles, they are not conductors at any state
Examples; O2, CO2, C2H6, H2O, SiC

13. Two Types of Covalent bonds
Polar Covalent
Non-polar Covalent

14. Polar Covalent

15. Non- polar Covalent

16. How do we determine bond type
Bond character can be predicted by subtracting the electronegativities of the two atoms involved in the bond.
Nonpolar covalent bond-difference of less than 0.5
Polar covalent bond-difference of
Ionic bond-difference of more than 2.1

17. Molecule
A neutral group of atoms joined together by covalent bonds.

18. Diatomic Molecules Molecules made up of two atoms.
There are 7 diatomic molecules.
H2, N2, O2, F2, Cl2, Br2, I2

19. Hydrogen Hydrogen Hydrogen
H· ·H  H:H
Hydrogen Hydrogen Hydrogen
Atom Atom molecule
The hydrogen molecule has a single covalent bond.
The electronegativity of each hydrogenatom is the same, so the electrons are shared.
Shared electron pair

20. Ionic Compounds
Molecular Compounds
Crystal Lattice
Molecule
Types of Elements
Metal with non-metal or polyatomic ions
Non-metal with non-metal
Physical State
Solid
Solid, liquid or gas
Melting Point
High
> 300 C
Low
<300 C
Solubility in water
Generally high
Generally low
Electrical conductivity of solution
Good conductor
Poor to none

22. Polar molecules have a positive end and a negative end.
A molecule for which this is true is a dipole.
The strength of this polarity is measured by the dipole moment.
The higher the dipole moment, the higher the polarity.
As the polarity of the molecule increases, so does its bond strength.

23. Naming binary covalent compounds
Table 6-5 on p. 212 gives the prefixes used in naming covalent compounds.
The first element named is usually the first one written in the formula-the least electronegative element
The root word is the name of the element.
The prefix is used to indicate how many atoms of that element are in the molecule.
The prefix mono- is not used in the first word of the name.

24. Naming binary covalent compounds
The last element in the compound is generally the element with the higher electronegativity.
It is given the suffix –ide, just as in binary ionic compounds.
The prefix is used to indicate how many atoms of that element are in the molecule.
The prefix mono- is used for the second element when only one atom of that element is present.

25. Example: CO
There is only one carbon. Since carbon is the first element, the prefix mono- is not used.
There is only one oxygen, but since this is the second element, the prefix mono- is used.
Because oxygen is the second element, we add the suffix -ide.
The name of this compound is:
Carbon monoxide

26. Example: P4O6
There is are 4 phosphorus atoms in this compound. The prefix for 4 is tetra-.
There are 6 oxygen atoms in this compound. The prefix for 6 is hexa-.
Because oxygen is the second element, we add the suffix -ide.
The name of this compound is:
Tetraphosphorus hexoxide