Transcript Review - TeacherWeb

a. protons
b. neutrons
c. electrons
d. morons
a. protons
b. neutrons
c. electrons
d. morons
a. electrons near the nucleus of the atom
b. middle energy level(s)
c. valence electrons
a. electrons near the nucleus of the atom
b. middle energy level(s)
c. valence electrons
a.
b.
c.
d.
1
4
8
10
1
b. 4
c. 8
d. 10
a.


Atoms are chemically stable (or resistant to change)
when their valence shells are completely filled with
electrons.
For most atoms, 8 electrons are needed to be
chemically stable.


The valence shells of the Noble gases are already
completely filled with electrons.
All of the Noble Gases, with the exception of helium,
have 8 valence electrons.
Helium has only two electrons.
 Therefore, the first energy level is full, making it stable with
its two valence electrons.

a. Bohr Models
b. Lewis Dot Diagrams
c. electron configuration
d. all of these
a. Bohr Models
b. Lewis Dot Diagrams
c. electron configuration
d. all of these
Sodium atom
Chlorine atom
a. Bohr Models
b. Lewis Dot Diagrams
c. both of these
a. Bohr Models
b. Lewis Dot Diagrams
c. both of these

have achieved a Noble Gas
configuration (which have a complete
set of valence electrons)
(In other words, atoms are stable when they
have bonded with other atoms to completely
fill their outer-level electron shells).
1.
Ionic Bonds = usually
metal + nonmetal
2. Covalent Bonds =
nonmetal + nonmetal
an atom that has gained or lost one
or more electrons, therefore it has a
positive or negative charge


Usually forms between a metal and a
nonmetal
Is the force of electrostatic attraction
between positively and negatively
charged ions
Na = sodium
Cl = chlorine


If an atom loses electrons it
becomes ____ charged.
If an atom gains electrons, it
becomes ____ charged.


If an atom loses electrons it
becomes _positively_ charged.
If an atom gains electrons, it
becomes _negatively_ charged.


Metals tend to lose electrons, becoming
a positive ion (cation).
Nonmetals tend to gain electrons &
become negative ions (anion).
1.
2.
3.
4.
5.
NaCl
CO2
H 2O
MgCl2
C4H10
1.
2.
3.
4.
5.
NaCl (ionic)
CO2 (covalent)
H2O (covalent)
MgCl2 (ionic)
C4H10 (covalent)

Superscript - “written above”

Examples: Na+, Mg2+, Cl-, O2-
Indicates the elements in a compound and
the ratio of the atoms of those elements in
one unit of the compound.
•
Examples: NaCl; H2O
•
The “2” in H2O is a subscript.
•
Subscript (“written below”)indicates the
number of atoms of an element in a unit
of that compound.
•
•
What is the ratio of sodium to chlorine
in NaCl?
What is the ratio of hydrogen to
oxygen in H2O?
•
•
What is the ratio of sodium to chlorine
in NaCl? 1:1
What is the ratio of hydrogen to
oxygen in H2O? 2:1
1. Determine the oxidation number of each ion (the
number of electrons an atom gains or loses)
The oxidation number for the representative
elements can be determined from its position on the
periodic table. Oxidation Numbers for transition
elements are determined from their negative ions.
1.
2.
3.
4.
Write the symbol of the positive ion first.
Write the symbol of the negative ion.
Add the superscripts. Is the sum zero?
If the sum does NOT equal zero, criss-cross the
ionic charges.
Check it: 2(+3) = +6
3(-2) = -6
+6 + -6 = 0
MUST BE IN THE LOWEST WHOLE-NUMBER RATIO
1.
Write the name of the positive ion first.
2.
If the positive ion has more than one common charge (i.e.,
transition metals), write the charge as a Roman Numeral. (All
transition metals except Ag1+, Zn2+ and Cd2+ have more than
one common ionic charge & must include Roman Numerals
to represent the charge of the ion).
3.
Write the root of the negative ion’s name.
4.
The ending is changed to -ide.
1.
sodium and chlorine
2.
calcium and chlorine
3.
aluminum and chlorine
Na 1+
Cl 1-
sodium ion
chloride ion
Formula: NaCl
Name of compound:
sodium chloride
Cl 1-
Ca 2+
Cl 1-
Formula: CaCl2
Name: Calcium Chloride
Cl 1-
Al 3+
Cl 1-
Cl 1-
Formula: AlCl3
Name: Aluminum Chloride



A group of atoms that shares a common ionic
charge.
Polyatomic ions must be memorized --- there’s
no way around it!
See the chart of common ions.







Ammonium ion: NH41+
Nitrate ion: NO31Nitrite ion: NO21Hydroxide ion: OH1Sulfate ion: SO42Carbonate ion: CO32Phosphate ion: PO43-
Na 1+
Sodium ion
NO31Nitrate ion
Chemical Name: sodium nitrate
Chemical Formula: NaNO3
NH4 1+
Ammonium ion
SO42Sulfate ion
NH4 1+
Ammonium ion
Chemical Name: ammonium sulfate
Chemical Formula: (NH4)2SO4
NH4 1+
PO43-
Ammonium ion
NH4 1+
Ammonium ion
1+
NH4
Ammonium ion
Phosphate ion
Chemical Name: ammonium phosphate
Chemical Formula: (NH4)3PO4
Ca 2+
calcium ion
NO3 1Nitrate ion
NO3 1Nitrate ion
Chemical Name: calcium nitrate
Chemical Formula: Ca(NO3)2

CuBr2 is named Copper (II) bromide
Cu2+ Br1-

FeCl3 is named iron (III) chloride
Fe3+ Cl1-
Writing Ionic Formulas Using the
Criss-Cross Method
Chemical Name: iron (III) sulfide
The Roman Numeral III, represents the
+3 charge iron has in this compound.

These transition elements ALWAYS
have the following oxidation numbers:
Ag+ Cd2+, Zn2+


AgBr is named silver bromide, and NOT
silver (I) bromide, because silver always has a
1+ oxidation number.
The same is true for compounds containing
Cadmium or Zinc. (Cd and Zn are always 2+)
Copper (I) and (II) = Cu+ and Cu2+
Iron (II) and (III) = Fe2+ and Fe3+
Chromium (II) and (III) = Cr2+ and Cr3+
Lead (II) and (IV) = Pb2+ and Pb4+
1.
FeS
2.
CuCl
3. PbBr4
1.
Iron (II) sulfide
2.
Copper (I) chloride
3.
Lead (IV) bromide
1.
lead (II) bromide
2.
chromium (II) sulfide
3.
copper (II) iodide
1.
PbBr2
2.
CrS
3.
CuI2

Result from the formation of ionic bonds.

Exist usually between a metal and a nonmetal

Are fun to name and write formulas for once
you know the rules!