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Chapter 4: Periodic Table
I. History of Development
A. Mendeleev – Beginnings
of the Modern Periodic
Table
1. Organization
2. Elements were
arranged in order of
increasing atomic mass
3. Predicted the
existence of
undiscovered elements
4. Properties of the
elements seemed to
repeat each other
II. Modern Periodic Table
A. Organization
1. rows (7) = Periods
2. columns (18) =
Groups and Families (7)
3. staircase = division
between metals, nonmetals, and metalloids
(semi-metals)
4. Modern Periodic
Law:
5. Atomic Number vs
Atomic Mass
6. Elements are
arranged in order of
increasing atomic
number
7. Why does the table
include the term
“Periodic”?
B. Electron Configurations
and the Periodic Table
1. Patterns
2. Noble gas or “Core”
configurations
C. Electron Dot diagrams
and the Periodic Table
1. pattern
D. Oxidation States
(Valence) and the Periodic
Table
1. Octet Rule
2. Patterns
3. Positive vs Negative
Ions
4. Elements with
multiple oxidation states
E. Metals vs Non-metals vs
Metalloids (Semi-metals)
1. Metals
a. left of the staircase
b. 1-3 electrons in their
outermost energy
level (excluding “d”
electrons)
c. electron donors: lose
e-
d. form positive ions by
losing electrons
(cations)
e. hard and shiny
f. good conductors of
heat and electricity
g. most are solids,
malleable and ductile
h. high melting and
boiling points
2. Non-metals
a. right of the staircase
b. 5-8 electrons in their
outermost energy
level
c. electron acceptors:
gain e-
d. form negative ions
(anions)
e. poor conductors of
heat and electricity
f. generally gases or
brittle solids
g. low melting and
boiling points
3. Metalloids (Semimetals) = have
properties of both
metals and non-metals
III. Trends or Patterns in the
Periodic Table
A. Certain properties of
elements in the periodic
table follow a predictable
pattern. Both chemical
and physical properties of
an element can be
predicted by its
“placement” in the table.
B. Atomic Radius and the
Periodic Table = atom size
1. patterns: increases
from top to bottom
and right to left
2. explanations: top
to bottom (adding
energy levels
increases atomic
radius); right to left
(adding protons
pulls energy levels in
closer, decreasing
atom size)
3. atoms and
positive/negative
ions: positive ions
are smaller than
their neutral atoms;
negative ions are
larger than their
neutral atoms
C. Ionization Energy and the
Periodic Table = energy
needed to remove the
outermost electron
1. patterns: increases
from bottom to top
and left to right
2. explanations:
bottom to top - in
higher energy levels,
e- are farther from
the nucleus – held
less tightly, more
“shielding effect”;
left to right – metals
lose e- more easily
than nonmetals
which tend to gain e-
D. Electron Affinity and the
Periodic Table =
attraction for e- (negative)
1. patterns (weak) –
in general, increases
from left to right
2. explanations:
metals tend to lose e; non-metals tend to
gain eE. Electronegativity and the
Periodic Table =
attraction for e- when
bonded to another atom
1. patterns: increases
from bottom to top
and left to right
2. explanations – see
ionization energy
F. Chemical Reactivity and
the Periodic Table –
ability to form bonds with
other atoms/elements
1. patterns
metals: increases
from top to bottom
and right to left
nonmetals:
increases from
bottom to top and
left to right
2. explanations –
ability to gain or lose
eIV. Chemical Families and
their Characteristics –
A. Alkali Metals (Group 1, or
IA)
1.
most reactive
metals
2.
oxidation state =
1+
3.
react with water
to form hydrogen gas
and a base
K + H2O  H2 + KOH
(base)
(alkali)
4.
shiny, silvery soft
solids that are
malleable, ductile,
and good conductors
of heat and electricity
5. sodium and
potassium are the
most abundant
6.
sodium
compounds are
important
commercially: NaOH
– paper; NaCO3 –
glass; NaSiO3 – soaps
B. Alkaline Earth Metals
(Group 2, IIA)
1. oxidation state = 2+
2. reactive, but not as
reactive as alkali metals
3. most abundant are
magnesium and calcium
which occur widely in
minerals (CaCO3,
MgCO3)
4. CaO is used in steel and
cement and in liming
lakes to reduce acid rain
5. CaCl2 is used to “salt”
roads
B. Halogens (Group 17, VIIA)
C. Halogens (Group 17, VIIA)
1. most reactive nonmetals
2. -1 oxidation state
3. Chlorine has many
industrial uses
4. diatomic = Cl2, F2, I2, etc.
5. reaction of most metals
with the halogens forms
“salts”
6. fluorine is the most
reactive nonmetal
element
7. chlorine is used to kill
bacteria in drinking
water
8. chlorofluorocarbons –
refrigerants and aerosols
(replaced because they
destroy the ozone layer)
D. Noble (Inert) Gases (Group
18, VIIIA)
1. least reactive group of
elements – energy levels
and orbitals are filled
2. Helium is the most
important
3. Can be used to protect
active metals in welding
4. Used in colored lights
E. Transition metals (Group
3-12, IIIB-IIB)
1. largest “family”
2. building or structural
metals
3. multiple oxidation states
because of losing “d”
electrons
4. commonly mixed in
“alloys”
5. zinc and chromium are
“corrosion” resistant
(resist oxidation)
6. iron = 4th most abundant
element in earth’s crust
Fe2O3); iron + carbon +
other metals = steel; Fe in
hemoglobin
7. coinage metals are Cu,
Ag, Au
8. adding “d” electrons
F. Inner Transition Metals
(Lathanides and Actinides)
1. Lanthanides – 3+
ions; soft, silvery metals;
fairly reactive; fairly
common in nature
2.Actinides – most are
radioactive; most are
synthetic produced from
bombarding uranium
with protons
G. Chalcogens (Oxygen
group) (Group 16 or VIA)
1. most plentiful
element in earth’s
crust (FeO, CaCO3,
etc)
2. needed as a gas for
aerobic respiration
(O2)
3. reactive, removes
two electrons from
other elements to
form O2- (oxidation)
4. O3 = ozone
(pollutant in
photochemical
smog; high in the
atmosphere it
protects us from uv
radiation)
5. O2 composes 21%
of our atmosphere,
produced primarily
from photosynthesis
by plants
6. sulfur compounds
are important
commercially
(H2SO4) = sulfuric
acid; sulfur oxides
are produced from
the burning of fossil
fuels and contribute
to the formation of
acid rain
SO2 + H2O  H2SO3
SO3 + H2O  H2SO4
H. Hydrogen is its own
family
1. it can either gain or
lose an electron
2. H  H+ and e3. H + e-  H4. it can form
covalent bonds by
sharing electrons H
+ H  H2
5. Hydrogen gas is
being used as an
alternative fuel (very
reactive)
H2 + O2  H2O +
energy
I.
Carbon group (group
IVA, 14)
1. carbon = basis of
all organic molecules
(most molecules in
living organisms are
based upon carbon)
2. easily forms 4
covalent bonds
3. two main inorganic
forms: diamond and
graphite (allotropes)
4. forms 5 main types
of organic
molecules:
hydrocarbons,
lipids, proteins,
nucleic acids, and
carbohydrates
5. silicon
a. metalloid or semimetal
b. abundant in earth’s
crust (SiO2) – quartz
c. important in
computer chips
J.
Nitrogen group (VA, 15)
1. nitrogen is
important in
proteins and nucleic
acids (organic
molecules)
2. nitrogen
compounds are
important plant
fertilizers and are
used in explosives
(TNT, dynamite)