Ionic Bonding
Chapter 6
Quick Review
• Atomic number = Total number of electrons
• The group number tells you the amount of valence
electrons an element has.
• The metals are on the left side of the periodic table
• The nonmetals are on the right side of the periodic
table.
• All elements need 8 electrons in their outer shell to be
stable. (Except H and He, they only need 2)
Valence Electrons
• Valence Electron- Any electron that is in the
outermost energy level of an atom.
• When the outer most (highest) energy level is full the
atom is stable. It will most likely not react
• What family (group) is least reactive? Why?
How many valence
electrons?
• List the number of valence electrons for the following
elements:
• 1. Potassium__________________
• 2. Silicon ____________________
• 3. Oxygen____________________
• 4. Boron______________________
• 5. Helium_____________________
Electron Dot Diagrams
• Also called Lewis Structures
• The “dots” represent the
• Element symbol represents the
electrons
and inner
Steps for drawing
dot diagrams
• 1. Figure out the number of valence electrons by
looking at the periodic table.
• 2. Write the element symbol
• 3. Put the dots around the symbol (dots= valence
electrons) * start at the top and work clockwise just
like the Bohr atom models.
• ** Remember: each space must be filed with 1 electron
before they can double up.
Examples
•
• Calcium
• Sulfur
• Neon
Remember the Rules
•
1. Figure out the number of valence
electrons by looking at the periodic
table.
•
2. Write the element symbol
•
3. Put the dots around the symbol
(dots= valence electrons) * start at
the top and work clockwise just like
the Bohr atom models.
•
** Remember: each space must be
filed with 1 electron before they can
double up.
Ion Formation
• Elements that do not have a full outer shell react with
other elements to become more stable.
- atoms want 8 valence electrons in
their outermost energy level
• Elements follow this rule by
electrons (donating or accepting electrons)
valence
• When this happens the number of protons and
electrons are
anymore. Atoms are no
longer overall neutral.
ion
- an atom that has a negative
or positive charge due to losing
or gaining an electron.
Lose or gain?
Element
Potassium (K)
Silicon (Si)
Oxygen (O)
Boron (B)
Hydrogen (H)
Carbon (C)
Nitrogen (N)
Gain or lose electrons?
How many electrons
need to be lost or gained?
H would like to
C would like to
N would like to
O would like to
Gain 1 electron
Gain 4 electrons
Gain 3 electrons
Gain 2 electrons
Ionic Bond
• Bond formed between 2 elements by the
• It’s between a
= Lose electrons
= Gain electrons
• The force that holds ions together.
How to draw an
ionic bond!!!!
• 1. Write out the symbols for the elements you are trying to bond.
• 2. Draw the Dot Diagram
• 3. Determine which element is the metal and which one is the
nonmetal (Which one is going to lose/gain electrons)
Drawing ionic bonds
• Show the transfer of electrons using arrows
•
Na
+
Cl
Na+
Cl-
1). Ionic bond – electron from Na is transferred to Cl, this causes a charge
imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged
particles or ions.
If an atom loses electrons:
• It becomes a positive ion = CATION
• These are elements that have 3 or less valence
electrons
• Elements that have 4 valence electrons can become
cations or anions depending on the situation!
If an atom gains electrons:
• It becomes a negative ion = ANION
• To name an anion, change the element’s name to
have “ide” at the end
• These are elements that have 5 or more valence
electrons
Formation of Ions from
Metals
• Ionic compounds result when metals react with nonmetals
• Metals lose electrons to gain a full outer electron shell (the
next electron shell becomes the new outer shell)
• Positive ions form when electrons are lost
Group 1A metals 
ion +1
Group 2A metals 
ion +2
Group 3A metals 
ion +3
Formation of Ions from
Nonmetals
• Nonmetals gain electrons to gain a full outer electron shell
• Negative ions form when electrons are gained
Group 5A nonmetals 
ion -3
Group 6A nonmetals 
ion -2
Group 7A nonmetals 
ion -1
• Group 8A elements do not gain or lose electrons since they
already have a full outer shell.
The formation of sodium chloride
(salt)
Properties of Ionic
Compounds
1. Individual atoms are bound tightly
together forming crystal structures
2. High melting points
3. High boiling points
4. Conduct electricity when melted or
in solution
5. Many can be dissolved in water