THE PERIODIC
TABLE
SCIENTISTS INVOLVED IN THE
PERIODIC TABLE DEVELOPMENT
 Newlands—English
scientist who first
arranged elements according to
increasing atomic mass (developed no
table or chart)
 Found similar element properties every 7
spaces apart; later became 8 spaces
apart after adding noble gases (AKA Law
of Octaves)
 Mendeleev—Russian
chemist who
arranged the known 63 elements based
on increasing atomic mass so that
elements with similar properties fell into
the same column on his table; gaps in his
table were elements that he predicted
the properties of (Sc, Ga, Ge)
 Periodic—repeating according to a
pattern
(Ex: days of the week)
 Ramsay—added
the last column to
Mendeleev’s table
 Moseley—British scientists who determined
the atomic #s of elements using X-rays; he
is who our modern table is based on
Periodic law
 States
that an element’s chemical and
physical properties are periodic functions
of their atomic #s
 As you go across a period (series)—start
with reactive metal solid and end with
nonreactive (inert) nonmetal gas
 Going down a group (family)---elements
have similar chemical and physical
properties
http://www.open.edu/openlearn/sciencemathstechnology/science/chemistry/alkalimetals
http://www.sciencegeek.net/Chemistry/ch
empdfs/PeriodicTrends.pdf
Metals
Nonmetals
Metalloids
magnetic
not
Means “metal-like”
Malleable AND
Ductile
brittle
Have at least 1
side of its element
box touching
staircase
(8 total because
Al is a metal)
Have luster
dull
White/gray in color
Good conductor
Good insulator
AKA semiconductors
High corrosion
Low corrosion
High density
Low density
High melting
pt./boiling pt.
Low melting
pt./boiling pt.
MeTals
Nonmetals (STINGY!!)
Electrons are
Taken away
Form PosiTively
charged cations
Found left of the
staircase line
React with acids
to form hydrogen
gas
GaiN electrons
Form Negatively
charged anions
Found right of the
staircase line
Do not
Family/Group Name
Characteristics
Alkali metals (1A)
Most reactive metal family
(Francium is most reactive); have 1
valence electron; +1 oxidation
number
Element
Families
(Groups)
Alkaline earth metals (2A)
Have 2 valence electrons;
+2 oxidation number
Transition Metals
AKA “B” groups; have varying
oxidation numbers
Boron family (3A)
Contains 1 metalloid and 4 metals;
3 valence electrons
+3 oxidation number
Carbon family (4A)
Contains 1 nonmetal, 2 metalloids,
& 2 metals;
4 valence electrons
+ and -4 oxidation number
Nitrogen family (5A)
5 valence electrons;
-3 oxidation number
Oxygen family (6A)
6 valence electrons; -2 oxidation
number
Halogens (7A)
Continued
Most reactive nonmetal family
(Fluorine is most reactive and
has highest electronegativity);
7 valence electrons
-1 oxidation number;
Name means “Salt formers” in
Greek
Noble Gases
AKA inert gases;
Do not react to form
compounds due to full valence
electron shell
All have 8 valence electrons
(Except He)
Lanthanide Series
AKA Rare earth metals;
belong in row 6 due to their
atomic number (sometimes
known as inner transition metals)
Actinide Series
Belong in row 7 due to their
atomic number (sometimes
known as inner transition metals);
Are radioactive
Representative Elements
(Main Group Elements)
 All
“A” groups because their “A” column
number represents how many valence
electrons they have
 Oxidation number---refers to how many
valence electrons are lost or gained in
order to bond
 Oxidation number pattern For “A” groups:
+1, +2, +3, + and -4, -3, -2, -1, 0
1A 2A 3A
4A 5A 6A 7A 8A
Atoms
Ions
Are electrically neutral
Can have positive or
negative charge
Protons = electrons
Have lost or gained
electrons
Atoms vs. Ions
Can be cations which
are
1. positive
2. have lost electrons
3. are characteristic of
metals
4. are smaller than the
original atom
Can be anions which are
1. Negative
2. Have gained electrons
3. Are characteristic of
nonmetals
4. Are larger than the
original atom
Practice Questions
 1.
Which is smaller:
S-1 OR S-2
 2.
Which is smaller: Sn+2 OR Sn+4
 3.
Which is larger: Al
 4.
OR Al+3
Which is larger: N-3 OR N