Transcript Lewis structures and Binary ionic Compounds

Ch 7
P194-206
At the end of this unit you will:
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Know and understand how to find the number of
valence electrons in an atom
Be able to create electron dot diagrams
Explain how cations and anions are formed
Write formulas and names for ionic compounds
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Valence electron
Electron dot structure
Ionic compound
Ionic bond
Chemical formula
Formula unit
Coordination number
Metallic bond
alloy
 The
absolute most important players in the
game of bonding are the___
 What
causes the “attraction” b/w atoms in a
bond?
 Define
valence electrons
 The
absolute most important players in the game
of bonding are the electrons
 What
causes the “attraction” b/w atoms in a
bond? The positive and negative charge
 Define
valence e-: the electrons in the outermost
energy level
 The
goal of every element on the PT is to
__________________
 Elements
achieve this goal by doing what?
 The
goal of every element on the PT is to
become more like a noble gas
 Elements
achieve this goal by doing what?
Losing or gaining electrons
 Cation: a
 Anion: a
positively charged ion
negatively charged ion
 Binary
ionic compounds are made up of 2
elements
 Typically
one element is a metal and the
other is a nonmetal
 Cations
and anions have opposite charges and
therefore attract one another. The force
holding the charges together is called an ionic
bond

An ionic bond is a transfer of electrons. We can
represent this by drawing a lewis structure (dot
diagram). Keeping in mind that the overall charge of
the compound must be neutral
Examples
Na
and F
of electron transfer
 Examples
 Ca
and Cl
of electron transfer
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Try these:
• K and I
• Al and O
1.
When naming, always place the cation name
first and the anion name second.
2.
The first element keeps its name form the PT
3.
The second element keeps its name the PT
but ends in -ide
Cs2O
BaS
Li3P
Cs2O
= cesium oxide
BaS = barium sulfide
Li3P = lithium phosphide
1.
When writing the formula, write the symbol of the
cation and then the symbol of the anion
2.
Next use subscripts to balance the charge of each
ion in the compound
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4.
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Write the formulas for compounds formed
from these pairs of ions;
Ba2+, S2Ca2+,N3Li+, O2Al3+, INow provide the names of each of the cmpds
you created
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1.
2.
3.
4.
Write the formulas for compounds
formed from these pairs of ions;
Ba2+, S2- = BaS – barium sulfide
Ca2+,N3- = Ca3N2 – calcium nitride
Li+, O2- = Li2O – lithium oxide
Al3+, I- = AlI3 – aluminum iodide