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Ionic Bonds
Slide Show #1
Atoms are neutral
• The # of protons = the # of electrons.
• + charges are equal to – charges.
• But, if an electron leaves, the atom becomes more positive.
electrons < protons
• When an atom gains an electron it becomes more negative
electrons > protons
• We call an atom that is charged an ion!
Electron Transfer
• Atoms with 5, 6, or 7 valence electrons do
not have enough to make a stable 8.
• Atoms with 1,2, or 3 valence electrons
can transfer their electrons to these
atoms.
• In any case the goal is to become stable!
Big Idea!
• Metals give electrons! (become positive)
• Nonmetals receive electrons!
(become negative)
Ionic Bonding
• Sodium can give up its
electron (becomes +).
• Chlorine can accept this
electron (becomes -)
• + & - attract and create
an ionic bond.
• Sodium Chloride is table
salt and is now neutral!
Ions and their charges
Name
Charge
Ionic form
Lithium
+1
Li+1
Sodium
+1
Na+1
Potassium
+1
K+1
Calcium
+2
Ca+2
Magnesium
+2
Mg+2
Aluminum
+3
Al+3
Fluorine
-1
F-1
Chlorine
-1
Cl-1
Oxide
-2
O-2
Sulfide
-2
S-2
Ionic Bonds – Some facts!
• Ionic compounds dissolve
easily in water.
• Ionic solutions (i.e. salt
water) easily conduct
electricity.
• Ionic compounds form
crystalline solids with high
melting temperatures.
Naming Ionic Compounds
Positive Ion first (usually metal)
Negative Ion last (usually nonmetal)
• If the negative ion is an element,
use –ide
• MgO is Magnesium Oxide
• NaCl is Sodium Chloride
• KS is Potassium Sulfide,
"Perhaps one of you gentlemen would mind telling me just
what is outside the window that you find so attractive...?"
How to write an ionic formula
• Write the charges for metal & non-metal
• Cross the charge of the metal to the
subscript of the non-metal
• Cross the charge of the non-metal to the
subscript of the metal.
• Now, simplify!
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