Transcript ion formation - Fort Bend ISD

ION FORMATION
an atom there are the same number of
protons and electrons
it is electrically neutral.
ION FORMATION
An ion is an atom that has lost or gained
electrons and now has an electric
charge
ION FORMATION
The net charge of an ion that has lost or
gained electrons is shown as a
superscript to the right of the atomic
symbol
It is also called the oxidation number
ION FORMATION
Bismuth will gain 3 electrons and have a
negative 3 charge
Bi =
Bi
-3
Sodium will lose its electron and become
positively charged
Na = Na
+1
Oxidation
number
ION FORMATION
The number of electrons that an atom
will gain or lose depends on its
position on the periodic table (group
number)
Ca+ion
An atom that has lost electrons and now
has a net positively charged
Sodium will lose its electron and become positively charged
Na =
+1
Na
Anion
An atom that has gained an electron and
now has a net negative charge
Bismuth will gain 3 electrons and have a
negative 3 charge
Bi =
Bi
-3
ION FORMATION
Metals, elements to the left of the
staircase, will form cations (+ charge)
Nonmetals, elements to the right of the
staircase will form anions (- negative)
ION FORMATION
group “B” elements
The oxidation numbers of the “B” group
elements are variable.
They do not follow a pattern like the
Group “A” elements.
ION FORMATION
group “B” elements
Oxidation numbers will be given to you
as a Roman Numeral in parentheses
following the name of the element.
ION FORMATION
group “B” elements
Practice
1. Write the ion formed by these element.

a.
iodine I-1
b. potassium
c. sulfur
S-2
d. cobalt (II) Co+2
K+1
e. gallium Ga+3
f. chromium (III) Cr+3
ION FORMATION
group “B” elements
Writing Ions Practice
ION
Bromine
Rubidium
Barium
Sulfur
Tin (IV)
Iodine
Argon
Aluminum
Magnesium
Oxidation
Number
1
1
2
2
4
1
0
3
2
Cation
or Anion
Anion
Cation
Cation
Anion
Cation
Anion
Neither
Cation
Cation
ION
Strontium
Lead (II)
Antimony (V)
Phosphorus
Copper (I)
Selenium
Oxidation
Number
2
2
5
3
1
2
Cation
or Anion
Anion
Cation
Cation
Anion
Cation
Anion
BONDING
Remember that a compound consist of
two or more elements chemically
combined together
H2O, NaCl, Sb3(PO4)5
BONDING
The smallest unit of a compound is a
molecule
Only electrons move during bonding
It is the movement of valence electrons
that determines how one atom will
bond with another
BONDING
Octet Rule- all atoms need 8 valence
electrons to be stable
BONDING, FOUR TYPES
IONIC- Transfer of electrons
COVALENT- sharing of electrons
POLAR COVALENT- uneven sharing of electrons
METALLIC- bonds between cations and free electrons
IONIC BONDS
Electrons are transferred from one atom
to another
This creates a Cation (+) and an
Anion (-)
Opposite charges attract
IONIC BONDING
Na
Na
Cl
+1
-1
Cl
-1
Na
+1
Cl
The Cation (Na) is attracted to the Anion (Cl)
IONIC BONDING
Ionic Bonds are the strongest bonds
Form between Metals and Non-Metals
The stair case
BONDING
separates Metals
(Left) from NonMetals (Right)
IONIC BONDING
Lewis Dot
Na
Na
Cl
-1
+1
Cl
BONDING
Energy Levels
Cl
Na
-1
+1
Na
Cl
Writing Formulas for
Ionic Compounds
Ion- an atom that has lost or gained
electrons
Cation- Lost electrons positive charge
Anion- Gained electrons negative charge
Writing Formulas for
Ionic Compounds
Oxidation number- indicates the number
of electrons lost or gained during
bonding
To be stable- oxidation number must be
zero (no charge)
Binary Compound– formed between
metal and non-metal
Writing Formulas for
Ionic Compounds
1.
2.
3.
Write the ion of the Cation – Mg+2
Write the ion of the Anion – O-2
Write the subscripts (bottom
numbers) to indicate how many ions
of each element is needed to make
the sum of the oxidation numbers
zero (do not write 1’s)
Writing Formulas for
Ionic Compounds
Magnesium (Mg)
Oxygen (O)
Group II
Group VI
Loses two electrons
Gains two electrons
Mg+2
O-2
Writing Formulas for
Ionic Compounds
Mg+2 + O
-2
= net charge of 0
Formula = MgO
Writing Formulas for
Ionic Compounds
Magnesium (Mg)
Bromine (Br)
Group II
Group IIV
Loses two electrons
Gains one electrons
Mg+2
Br
-1
Writing Formulas for
Ionic Compounds
Mg+2 + Br
-1
We need 2 Br
-1
Mg+2 + Br2
= net charge of +1
ions to even out the charge
= net charge of 0
-1
(Mg+2 + Br
-1
+ Br
Formula = MgBr2
-1
= net charge of 0)
Writing Formulas for
Ionic Compounds
Combine Sodium and Oxygen
Sodium (Na)
Oxygen (O)
Group I
Group VI
Loses one electrons
Gains two electrons
Na+1
O
-2
Writing Formulas for
Ionic Compounds
Na+1 + O
-2
We need 2 Na
+1
Na2+2 + O
-2
= net charge of -1
ions to even out the charge
= net charge of 0
(Na+1 + Na+1 + O
Formula = Na2O
-2
= net charge of 0)
Writing Formulas for
Ionic Compounds
Combine Calcium and Fluorine
Calcium (Ca)
Fluorine (F)
Group II
Group VII
Loses two electrons
Gains one electrons
Ca+2
F
-1
Writing Formulas for
Ionic Compounds
Ca+2 + F
-1
We need 2 F
-1
Ca+2 + F2
= net charge of +1
ions to even out the charge
-1
= net charge of 0
(Ca+2 + F-1 + F
Formula = CaF2
-1
= net charge of 0)
Writing Formulas for
Ionic Compounds
Combine Iron (II) and Sulfur
Iron (II) (Fe II)
Sulfur (S)
Fe (II)
Group VI
Loses two electrons
Gains two electrons
Fe+2
S
-2
Writing Formulas for
Ionic Compounds
Fe+2 + S
-2
= net charge of 0
Formula = FeS
Writing Formulas for Ionic
Compounds: Crisscross
A SHORTCUT to figure out then number
of each ion needed to form a neutral
compound
Writing Formulas for Ionic
Compounds: Crisscross
1.
2.
3.
Write each Cation first followed by
the Anion
Cross the oxidation numbers
(superscript) to be the subscript of
the other
Reduce the subscripts if they aren’t
already
Writing Formulas for Ionic
Compounds: Crisscross
Magnesium (Mg)
Bromine (Br)
Group II
Group IIV
Loses two electrons
Gains one electrons
Mg+2
Br
-1
Writing Formulas for Ionic
Compounds: Crisscross
+2
Mg
Mg 1
Br
-1
Br2
Formula = MgBr2
Writing Formulas for Ionic
Compounds: Crisscross
Magnesium (Mg)
Oxygen (O)
Group II
Group VI
Loses two electrons
Gains two electrons
Mg+2
O-2
Writing Formulas for
Ionic Compounds
Mg+2 + O
-2
Mg+2 + O-2
Formula = Mg2 O2
(REDUCE)
=MgO
Writing Formulas for Ionic
Compounds: Crisscross
Combine Sodium and Oxygen
Sodium (Na)
Oxygen (O)
Group I
Group VI
Loses one electron
Gains two electrons
Na+1
O
-2
Writing Formulas for
Ionic Compounds
Na+1 + O
-2
Na2 + O1
Formula = Na2O
Writing Formulas for
Ionic Compounds
Combine Iron (II) and Sulfur
Iron (II) (Fe II)
Sulfur (S)
Fe (II)
Group VI
Loses two electrons
Gains two electrons
Fe+2
S
-2
Writing Formulas for
Ionic Compounds
Fe+2 + S
Fe2 + S2
Fe2S2
REDUCE to
FeS
-2
Naming Ionic Compounds
1.
Write the name of the cation first
Naming Ionic Compounds
2. If the cation is a transition metal add
a Roman Numeral in parentheses to
indicate oxidation number
a) Use crisscross method in reverse
FeS = Fe+1 S-1
Naming Ionic Compounds
b) Check negative ion to see if it has
correct oxidation number; multiply
the charges by the correct number
till it does
FeS = Fe+1 S-1 should be S-2
2 x (Fe+1 S-1 ) = Fe+2 S+2
Naming Ionic Compounds
c) Remember the Roman numeral only
goes in the name, not the formula
(TRANSITON METAL ONLY)
FeS = Fe+2 S+2
Naming Ionic Compounds
3.
Write the name of the anion
Take the root word of the element name
and end it with –ide
FeS = Iron (II) sulfide
Naming Ionic Compounds
NaF
1.
2.
3.
MgO
Sodium
Sodium is not a
transition metal
Fluoride
Sodium Fluoride
1.
Magnesium
2.
Magnesium is not
a transition metal
3.
Oxide
Magnesium Oxide
Naming Ionic Compounds
CuCl2
1. Copper
2. Copper is a transition metal
a) CuCl2 = Cu+2 Cl-1
b) Cu+2 Cl-1 is correct
c) Copper (II)
3. Chloride
Copper (II) Chloride
Naming Ionic Compounds
PbO
1.
Lead
2.
Lead is a transition metal
a) PbO = Pb+1 O-1
b) Pb+1 O-1 is not correct
2(Pb+1 O-1) = Pb+2 O-2
c) Lead (II)
3. Oxide
Lead(II) Oxide
Naming Ionic Compounds
ZnS


Zinc
Zinc is a transition metal
a) ZnS = Zn+1 S-1
b) Zn+1 S-1 is not correct
2(Zn+1 S-1) = Zn+2 S-2
c) Zinc (II)
3. Sulfide
Zinc (II) sulfide
Naming Ionic Compounds
K3N
 Potassium
 Potassium is not a transition metal
3. Nitride
Potassium Nitride
Naming Ionic Compounds
BaO
 Barrium
 Barrium is not a transition metal
3. Oxide
Barrium Oxide
Naming Ionic Compounds
CaO
 Calcium
 Calcium is not a transition metal
3. Oxide
Calcium Oxide
Naming Ionic Compounds
AlF3
 Aluminum
 Zinc is not a transition metal
3. Fluoride
Aluminum Fluoride
Naming Ionic Compounds
CuI2

Copper

Copper is a transition metal
a) CuS2 = Cu+2 I-1
b) Cu+2 I-1 is correct
c) Copper (II)
3. Iodide
Copper (II) Iodide
Naming Polyatomic
Compounds
Polyatomic compounds have more than
2 different types of elements in the
formula Ex. H2SO4
NH4+1 is the only Polyatomic ion that is a
Cation
All others will come after the metal ion
Name
Ammonium
Acetate
Chlorate
Hydroxide
Nitrate
Carbonate
Sulfate
Sulfite
Phosphate
Nitrite
Chlorite
Cyanide
Formula
NH41+
C2H3O21ClO31OH1NO31CO32SO42SO32PO43NO21ClO21CN1-
Naming Polyatomic
Compounds
Name a polyatomic compound just like
you would an ionic compound but
you do not change the ending of the
Polyatomic ion
ZnSO4
1.
2.
From the ion chart SO4 is an polyatomic ion
Zinc
Zinc is a transition metal
a) Zn(SO4) = Zn+1 (SO4) -1
b) Zn+1 (SO4) -1 is not correct
From the ion chart (SO4) -2
2(Zn+1 SO4-1) = Zn+2 SO4-2
c) Zinc (II)
3. Sulfate… From the chart
Zinc(II) sulfate
Naming Polyatomic
Compounds
NaOH
From the ion chart OH is an polyatomic ion
2.
Sodium
Sodium is not a transition metal
3.
3. OH… Hydroxide… From the chart
1.
Sodium Hydroxide
Naming Polyatomic
Compounds
CaCO3
From the ion chart CO3 is an polyatomic ion
2.
Calcium
Calcium is not a transition metal
3.
3. CO3 from the chart = Carbonate
1.
Calcium Carbonate
Naming Polyatomic
Compounds
KCl02
From the ion chart ClO2 is an polyatomic
ion
2.
Potassium
Potassium is not a transition metal
3.
3. ClO2 from the chart = Chlorate
1.
Potassium Chlorate
Naming Polyatomic
Compounds
Al(OH)3
From the ion chart OH is an polyatomic ion
2.
Aluminum
Aluminum is not a transition metal
3.
OH from the chart = Hydroxide
1.
Aluminum Hydroxide
Naming Polyatomic
Compounds
Mg3(PO4)2
From the ion chart PO4 is an polyatomic ion
2.
Magnesium
MAgnesium is not a transition metal
3.
3. PO4 from the chart = Phosphate
1.
Magnesium Phosphate
Binary Compounds with
Polyatomic Ions

Covalently-bonded groups of atoms
that behave as a unit and carry a
charge
NO3-1
Binary Compounds with
Polyatomic Ions

The Charge that is shown is for the
whole group not just the last atom
(NO3)-1
Binary Compounds with
Polyatomic Ions
Polyatomic ions have very specific
names. (LIST ON YOUR NOTES)
Binary Compounds with
Polyatomic Ions
1.
To write the formula, use the criss
cross method for Polyatomic ions just
like you did for regular ions.
2.
Never change anything within the
polyatomic ion
3.
Add subscripts outside parentheses
Binary Compounds with
Polyatomic Ions
Magnesium Phosphate
Mg
+2
Mg3(PO4)2
PO4
-3
Binary Compounds with
Polyatomic Ions
Magnesium Carbonate
Mg
+2
Mg2(CO3)2
Mg(CO3)
CO3
-2
Reduce
Binary Compounds with
Polyatomic Ions
Calcium Hydroxide
Ca
+2
Ca(OH)2
OH
-1
Binary Compounds with
Polyatomic Ions
Manganese(IV) Sulfite
Mn
+4
Mn2(SO3)4
SO3
-2
Covalent Bonds
Electrons are shared between atoms but
not transferred
Electrons are located in the outermost
energy levels of both atoms at the
same time
Form between nonmetals
Covalent Bonds
NH3
Lewis Dot
H
H N
H
Covalent Bonds
NH3
Energy Level
H
H
N
H
Covalent Bonds
Ionic vs. Covalent Properties
Covalent Bonds
Ionic Bonds
type of elements
Nonmetals only
Metals and
Nonmetals
type of bonding
share electrons
transfer electrons
structure
not rigid – solid,
liquid or gas
crystalline
melting point
low
high
hardness
soft  hard
very hard
conduct
electricity?
no
yes (when dissolved in
water)
Covalent Bonds: Diatomic
Atoms
There are 7 elements that can form
covalent bonds between its atoms
Hydrogen
Atoms
H·
·H
Molecule
H:H
Covalent Bonds: Diatomic
Atoms
Nitrogen
Atoms
·
·
:N·
·N:
·
·
Molecule
:N:::N:
Forms a triple bond
Covalent Bonds: Diatomic
Atoms
··
··
O::O
··
··
··
··
:F:F:
··
··
··
··
:Cl : Cl :
··
··
··
··
: Br : Br:
··
··
·· ··
:I:I:
·· ··
OXYGEN
(Double bond
between
atoms)
FLOURINE
CHLORINE
BROMINE
IODINE
Determine ionic or
covalent bonds
N2O5
Covalent (nonmetals)
A liquid at toom temp
Covalent (liquid)
PbNO3
Ionic (Metal with
nonmetal)
Determine ionic or
covalent bonds
A salt that conducts
electricity in solution
Ionic (conducts
electricity)
KF
Ionic (metal with
nonmetal)
AgCl
Ionic (Metal with
nonmetal)
Determine ionic or
covalent bonds
Gasoline
Covalent (liquid)
PCl3
Covalent (metal to
metal)
O2
Covalent (share
electrons)
Naming Covalent
Compounds
Oxidation numbers are not used in
determining the formula unit
Two nonmetals can combine in more
than 1 way
We use prefixes to name and indicate
the number of atoms of each type
Naming Covalent
Compounds
Prefix
Number
mono
1
di
2
tri
3
tetra
4
penta
5
hexa
6
hepta
7
octa
8
nona
9
deca
10
Naming Covalent
Compounds
Write the name of the element that is
farthest left first
Write the other element second and
change the ending to –ide
Add prefixes to the two elements
Do not use mono on first element
Naming Covalent
Compounds
CO2
Element to left first, then the second element with an
–ide ending
Carbon
Oxide
Add prefixes
Monocarbon
Dioxide
Drop Mono from first element
Carbon dioxide
Naming Covalent
Compounds
CF4
Element to left first, then the second element with an –ide
ending
Carbon
Flouride
Add prefixes
Monocarbon
Tetraflouride
Drop Mono from first element
Carbon Tetraflouride
Naming Covalent
Compounds
SiCl3
Element to left first, then the second element with an
–ide ending
Silicone
Chloride
Add prefixes
Monosilicone trichloride
Drop Mono from first element
Silicon Trichloride
Naming Covalent
Compounds
CO2
Element to left first, then the second element with an
–ide ending
Carbon
Oxide
Add prefixes
Monocarbon
Dioxide
Drop Mono from first element
Carbon dioxide
Naming Covalent
Compounds
CO2
Element to left first, then the second element with an
–ide ending
Carbon
Oxide
Add prefixes
Monocarbon
Dioxide
Drop Mono from first element
Carbon dioxide
Naming Covalent
Compounds
H2O
Element to left first, then the second element with an –ide
ending
Hydrogen Oxide
Add prefixes
Dihydrogen
oxide
Drop Mono from first element
Dihydrogen oxide
Naming Covalent
Compounds
Common names to remember
H2O = Water
NH3 = Ammonia
CH4 = Methane
Writing Formulas for Binary
Covalent Compounds
List the symbol of the first element in
the name first and then second
element next
Use the subscripts to identify the prefix
in the name for that atom
Writing Formulas for Binary
Covalent Compounds
Carbon Tetrachloride
C
Cl
Tetra= 4
CCl4
Writing Formulas for Binary
Covalent Compounds
Dinitrogen Trioxide
N
Di = 2
N2O3
O
Tri = 3
Writing Formulas for Binary
Covalent Compounds
Iodine Pentaflouride
I
F
Penta = 5
IF5
Writing Formulas for Binary
Covalent Compounds
Hexaboron Silicide
B
Hexa = 6
B6Si
Si
Writing Formulas for Binary
Covalent Compounds
Diantomny Pentoxide
Sb
Di = 2
Sb2O5
O
Penta = 5
Writing Formulas for Binary
Covalent Compounds
Ammonia
NH3
Polar Covalent Bonds
A type of covalent bond where electrons are
shared unequally between atoms
Electrons spend more time with one atom
than the other
The stronger atom will be slightly negative
and the other will be slightly positive
Polar covalent Bonds
Water: the electrons hang around the
oxygen atom more than the hydrogen
atom
Example of Polar Covalent Bond in Action
Polar Covalent Bond
Water
Lewis Dot
O
H
H
Metallic Bonds
Bonds between positive ions and freeroaming electrons
These are flexible and are good
conductors as solids (electrons are
free to move