Atomic Number: the number of protons

The number of electrons is equal to the number of protons
Mass Number: the # of particles in the nucleus

The mass number -the atomic number = the number of neutrons
Groups: vertical columns


have the same number of valence (outer) ehave similar properties
Periods: horizontal rows

have the same number of energy levels
1
Atomic
Number
Chemical
Symbol
1.0079
Mass
Number



atoms with the same number of protons but
a different # of neutrons
number of neutrons changes the mass but
not the charge
this is the reason that the mass number is not
a whole number
Carbon -12
6 protons and 6 neutrons
6+6=12
Carbon-14
6 protons and 8 neutrons
6+8= 14
Period: a row of elements on the periodic chart
▪ = number of energy levels
Group: a column of elements on the periodic chart
▪ have similar characteristics
▪ = number of valence (or outer) electrons
Energy Levels: the route around the nucleus of
an atom that an electron travels
▪ the bigger the orbit the more energy in the electron
Orbitals: places within an energy level where
electron tends to be found
▪ it is impossible to pinpoint exactly where an electron is
located
Valence Electrons: electrons in the outermost
orbital
▪ determine properties of the element
Orbitals
Energy
Level
Number
of
Electrons
s
p
d
f
1
2
3
4
5
6
7
8
2
8
18
32
32
18
8
2
2
2
2
2
2
2
2
2
x
6
6
6
6
6
6
x
x
x
10
10
10
10
x
x
x
x
x
14
14
x
x
x
s
p
d
f
1s2
2s2
2p6
3s2
3p1
2
2
6
1s 2s 2p
The energy levels
The outermost energy level
(this level houses the valence electrons)
2
1
3s 3p
The orbital
The number of
electrons
The valence
electrons
The d and f orbitals lag behind
2
2
6
2
6
2
10
6
1s 2s 2p 3s 3p 4s 3d 4p
2
10
6
2
14
10
6
5s 4d 5p 6s 4f 5d 6p
2
14
10
6
7s 5f 6d 7p
Key
Lagging 1 Level Behind
Lagging 2 levels Behind
1.
2.
3.
Full Energy Level
Full Sublevels
Half Full Sublevels
Expect: [Ar] 4s2 3d9
Actually: [Ar] 4s1 3d10
Fill the lower level to increase stability
Expect: [Ar] 4s2 3d4
Actually: [Ar] 4s1 3d5
Half fill the lower level to increase stability



Find the noble gas that occurs directly before the
element given.
Place the chemical symbols for the noble gas in
brackets.
Continue the configuration from that point.
Example: Uuo
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6
OR
[Rn] 7s2 5f14 6d10 7p6



Atoms bond in order to become stable
An atom is stable when it has 8 outer
electrons (so the noble gases do not bond)
Bonds are formed when electrons are:
▪ Transferred: ionic bond
 Forms 2 types of ions (atoms with a charge):
 Cation = +
 Anion = ▪ Shared: covalent bond
 2 types of covalent bonds
 Polar: e- shared unequally
 Nonpolar: e- shared equally
a group of chemically united (BONDED) atoms
(forms a compound)
Do the lab activity on p. 188
Answer the Group Analysis Questions(1-2)
Do Periodic Trends Lab Activity on p. 191
Answer Group and Individual Questions (1-4)



The most electronegative element on the
chart is Fluorine (F).
The least electronegative element on the
charts is Francium (Fr).
The greater the difference in
electronegativities between elements the
greater chance of an ionic bond.
Reactants  Products
Yield


Chemical Reactions result in chemical change
ALL Chemical Reactions MUST BE
BALANCED
p. 196
Answer Group Analysis and Individual Analysis
Questions
http://player.discoveryeducation.com/index.cfm?guidAssetId=2ED4D53B-8E79453D-B7EE-4DF53F92A9C4&blnFromSearch=1&productcode=US
The valence electrons in an atom have
HIGH POTENTIAL ENERGY
By bonding with other atoms, potential
energy is decreased creating stable
compounds.
Symbols of atoms with dots to represent the
valence-shell electrons.
(The valence- are the e- directly involved in bonding).
Ar
Mg
C
The Noble Gases do not react with other
elements because they are already
STABLE.
The outer most “s” and “p” orbitals are completely filled with 8
electrons, satisfying the octet rule.
Ne
Elements combine with each other to achieve
noble gas electron configurations
or
(8 outer e-)
**The exceptions to the octet rule are
Hydrogen and Helium
(they only need 2)
•
The forming of chemical compounds results
in chemical change.
•
Compounds are made up of chemically
united elements
Compounds have completely different
characteristics than its component elements
•
•
Compounds are NEUTRAL
2H2O = H2O = HHO
H2O HHO
Subscript = # of atoms
Coefficient = # of molecules
N: 1
H: 5
O: 1
The Gaining and Losing of Electrons
to form IONS.
(An ion is an atom with a charge.)
•
•
•
•
Soluble in water
Do not transmit electric current
Brittle
High melting and boiling points
Ionization Energy: the amount of energy
needed to remove an e- from an atom.
Metals
have a low
ionization
energy
Nonmetals
have high
ionization
energy
because
they are
closer to
satisfying
the octet
rule!
the higher the electronegativity the greater the
ability to pull electron to itself
The nature of a bond is determined by differences in electronegativity.
The GREATER the electronegativity difference, the MORE ionic the bonding.
Ionic compounds result when metals react with
nonmetals
Metals lose electrons to achieve a stable outer energy
level
• Positive ions form when electrons are given away
•
Group 1 metals  ion 1+
Group 2 metals  ion 2+
Group 13 metals  ion 3+
1. Write the symbol for the cation (+) followed by the
symbol for the anion (-).
2. Put any polyatomic ions (see green boxes) in
parenthesis
3. Write the oxidation numbers above the appropriate
ions
4. Use the criss-cross method to deterimine # of
atoms (do not criss-cross ones)
5. Make sure the sum of all ox# is ZERO.
6. Reduce
http://www.youtube.com/watch?v=gAHQRLZf9U0
Sodium
Atom
Sodium
Ion
Na 
11 p+
11 e0
– e


Na +
11 p+
10 e1+
Na 
+

1+
Na
1-
YOUR TURN…
Using dot diagrams, draw the Lewis structures that result when the
following elements form ionic bonds:
A. Potassium + chlorine
B. Magnesium + fluorine
Potassium + Chlorine
K
Cl
+
K
Cl
Magnesium + Fluorine
Mg
+
F
Mg F
Oxidation: the process of losing electrons
▪ Creates an ion with a + charge
▪ Creates cations
Reduction: the process of gaining electrons
▪ Creates an ion with a – charge
▪ Creates anions
1. Write the name of the cation (+)
2. Write the name of the anion (-) with an ide suffix
NaCl
Sodium and Chlorine
Sodium Chloride
The oxidation number is not always the same, it
varies.
The variable oxidation states are represented with a
roman numeral in parentheses and are located in
groups
3-12 on the periodic chart.
Copper
Copper (I) = Cu+ Copper (II) = Cu2+



Write the symbol for the cation followed by
the symbol for the anion.
Write the oxidation numbers above the
appropriate ions.
Criss-Cross
3+
2-
Copper(III) Oxide: CuO Cu2O3
1+
2-
Copper(I) Oxide: CuO Cu2O
SO4
C2H302
NO3
NO2
NH4
HCO3
CO3
OH
ClO3
PO4
Sulfate
Acetate
Nitrate
Nitrite
Ammonium
Bicarbonate
Carbonate
Hydroxide
Chlorate
Phosphate
21111+
12113-
1. Write the name of the cation (+)
2. Write the name of the anion (-)
3. If either is a polyatomic ion write the name of the
polyatomic ion (you don’t need to change any
suffixes)
Na(OH)
Sodium Hydroxide
Write the symbol for the cation followed by the symbol
for the anion.
 Put all polyatomic ions in parentheses!!
 Write the oxidation numbers above the appropriate
ions.
 Criss-Cross

2+
3-
1+
3-
Calcium Phosphate: Ca(PO4)
Ammonium Phosphate: (NH4)(PO4)
Ca3(PO4)2
(NH4)3(PO4)
1+
1-
=0
Cu(OH)
3+
62-
Ni2O3
Copper (I) Hydroxide
=0
Nickel (III) Oxide
sharing of electrons




Between nonmetallic elements of similar
electronegativity.
Formed by sharing electron pairs
Stable non-ionizing particles, they are not
conductors at any state
Examples; O2, CO2, C2H6, H2O, SiC
Water is a polar molecule because oxygen is more electronegative than hydrogen, and
therefore electrons are pulled closer to oxygen.

A polar molecule has a (+) and a (-) end.

A nonpolar molecule does not have charged ends.
Metal + Nonmetal --> ionic compound
(usually)
Metal + Polyatomic ion —> ionic compound
(usually)
Nonmetal + Nonmetal —> covalent compound
(usually)
Hydrogen + Nonmetal —> covalent compound
(usually)

The chemical symbol for the atom is
surrounded by a number of dots
corresponding to the number of valence
electrons
1. Write the name of the cation (+) with
appropriate prefix (do NOT use mono for the
cation)
2. Write the name of the anion (-) with the
appropriate prefix
CO2
Carbon Dioxide
1:
2:
3:
4:
5:
6:
mono
di
tri
tetra
penta
hexa



Formula weight is the sum of the atomic
masses.
Example- CO2
Mass, C + O + O
12.011 + 15.994 + 15.994
43.999
Reactants: substances about to react
Products: new substances produced
Reactants
YIELD
Products
mass can neither be created nor destroyed in
a chemical reaction