ionic compounds. review of atomic structure the structure of the atom neutrons + protons are in the...
DESCRIPTION
Atoms in groups 1 – 13 (metals) will lose electrons in order to achieve a full outer shell They become cations (positive) Atoms in groups 15 – 17 (nonmetals) will gain electrons in order to achieve a full valence shell They become anions (negative) Combining Capacity: the number of electrons an atom needs to gain or lose to achieve a full outer shell The positive and negative ions attract to form an ionic bond IONIC COMPOUNDS – The Octet RuleTRANSCRIPT
IONIC COMPOUNDS
REVIEW OF ATOMIC STRUCTURE The structure of the atom
Neutrons + Protons are in the nucleusElectrons in orbits around the nucleus
Neutrons = Zero Charge
Protons = Positive ChargeElectrons = Negative Charge
Atoms in groups 1 – 13 (metals) will lose electrons in order to achieve a full outer shell They become cations (positive)
Atoms in groups 15 – 17 (nonmetals) will gain electrons in order to achieve a full valence shell They become anions (negative)
Combining Capacity: the number of electrons an atom needs to gain or lose to achieve a full outer shell
The positive and negative ions attract to form an ionic bond
IONIC COMPOUNDS – The Octet Rule
IONIC COMPOUNDS – Ionic Charges of the Elements+1
+2 +3 -3 -2 -1
IONIC COMPOUNDS – The Formation of an Ionic Bond
IONIC COMPOUNDS – The Formation of an Ionic Bond Ionic compounds are formed when a metal
(M) is bonded to a nonmetal (N)
In general:
M N MN
M N MN
Rules Assign ionic charges to each atom Apply the criss-cross rule (ONLY the numbers
travel, NOT the sign) Reduce the subscripts by dividing by the highest
common factor Write your chemical formula
IONIC COMPOUNDS – Writing Chemical Formulas
Example 1: sodium and chlorine
IONIC COMPOUNDS – Writing Chemical Formulas
Na Cl+1 -1
Na Cl1 1
ClNa
Example 2: calcium and chlorine
IONIC COMPOUNDS – Writing Chemical Formulas
Ca Cl+2 -1
Ca Cl1 2
ClCa 2
Example 3: lithium and oxygen
IONIC COMPOUNDS – Writing Chemical Formulas
Li O+1 -2
Li O2 1
OLi 2
Example 4: magnesium and oxygen
IONIC COMPOUNDS – Writing Chemical Formulas
Mg O+2 -2
Mg O2 2
OMg
Remember to find the HIGHEST COMMON FACTOR
OMg2 2
Rules…1. Write the metal’s name first2. Write the nonmetal’s name second (change the
ending to “-ide”)
For example: NaCl = sodium chloride
IONIC COMPOUNDS - Naming
IONIC COMPOUNDS - Naming
CaCl2
Li2O
MgO
Calcium chloride
Lithium oxide
Magnesium oxide
Chemical Formula Chemical Name
Some metals can have different combining capacities in different compounds
For example: Copper (Cu) = 1, 2 Iron (Fe) = 2, 3 Lead (Pb) = 2, 4 Tin (Sn) = 2, 4
In these cases, the combining capacity must be specified using Roman Numerals
IONIC COMPOUNDS – Multivalent Metals
These numbers are written as Roman Numerals (i.e. I, II, III, IV, V)
IONIC COMPOUNDS – Multivalent Metals Iron(II) chloride Iron(III) chloride
Iron has two combining
capacities. Iron can have a +2 or
+3 charge.
-1
Fe Cl1 2
ClFe 2
Fe Cl+2 -1
Fe Cl1 3
Fe Cl+3
ClFe 3
“IONIC COMPOUNDS” Worksheet
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