Gilbert Newton Lewis (surrounded by pairs of electrons)

1
Lewis Dot Structures Covalent Bonding
Gilbert Newton Lewis (surrounded by pairs of
electrons)
2
Lewis-Dot Structures

• Find out which group (column) your element is in.
• This will tell you the number of valence
  electrons your element has.
• You will only draw the valence electrons.

3
Groups - Review
Group 8 8 electrons
Group 1 1 electron
Except for He, it has 2 electrons
Group 2 2 electrons

• Each element in a group has the same number of
  electrons in their outer orbital, also known as
  shells.

3 4 5 6 7

• The electrons in the outer shell are called
  valence electrons

4
Lewis-Dot Structures

1. Write the element symbol.
2. Carbon is in the 4th group, so it has 4 valence
   electrons.
3. Starting at the right, draw 4 electrons, or dots,
   counter-clockwise around the element symbol.

C
5
Lewis-Dot Structures

• Try these elements on your own
• H
• P
• Ca
• Ar

H
6
Lewis-Dot Structures

• Try these elements on your own
• H
• P
• Ca
• Ar

P
7
Lewis-Dot Structures

• Try these elements on your own
• H
• P
• Ca
• Ar

Ca
8
Lewis-Dot Structures

• Try these elements on your own
• H
• P
• Ca
• Ar

Ar
9
Lewis-Dot Structures

• Symbols of atoms with dots to represent the
  valence-shell electrons
• 1 2 13 14 15
  16 17 18
• H? He
• ? ? ?
  ? ? ? ? ? ? ?
  ?
• Li? Be? ? B ? ? C ? ? N ?
  O ? F ? Ne
• 
  ? ? ? ? ?
  ? ?
• ? ? ?
  ? ? ? ? ? ?
  ? ?
• Na? Mg? ? Al? ? Si ? ?P?
  S? Cl ? Ar
• ?
  ? ? ? ? ? ?

10
In an IONIC bond, electrons are lost or
gained, resulting in the formation of IONS in
ionic compounds.
11
F
K
12
F
K
13
F
K
14
F
K
15
F
K
The compound potassium fluoride consists of
potassium (K) ions and fluoride (F-) ions
16
_

F
K
The ionic bond is the attraction between the
positive K ion and the negative F- ion
17
In covalent bonding, atoms still want to be
like a noble gas (the octet rule).
But rather than losing or gaining electrons,
atoms now share an electron pair.
18
Covalent bonding example
Carbon
19
Covalent bonding example
Carbon now has an octet.
C
All hydrogen atoms now have 2 electrons