INTRODUCTION TO THE
PERIODIC TABLE
CHEMISTRY I
3rd STAGE
Objectives
• Describe the origin of the periodic table.
• Identify the position of groups, periods,
and the transition metals in the periodic
table.
Development of the Periodic Table
• Elements such as gold,
silver, tin, copper, lead
and mercury have been
known since antiquity.
• During the next 200
years, a vast body of
knowledge concerning
the properties of
elements and their
compounds was acquired
by chemists.
• The first scientific
discovery of an element
occurred in 1649 when
Hennig Brand discovered
phosphorous.
Hennig Brand
Alchemy Symbols
• The period of chemical history
we call alchemy spans about
three centuries, roughly AD
1400 to AD 1650.
• In the early days of alchemy,
the astronomical signs of the
planets were also used as
alchemical symbols.
• Then in the centuries of
medieval persecution and
suppression every alchemist
invented his own secret
symbols.
Early Attempts of Organization
• As the number of known
elements grew, scientists
began to recognize
patterns in properties and
began to develop
classification schemes.
• In the famous atomic theory
of John Dalton (1805), it
was suggested that the
atoms of an element have a
characteristic mass. So,
attempts were made to
classify elements on the
basis of their atomic
masses.
John Dalton, a Quaker teacher and
the first to assign atomic weights to
elements, created this table in 1808
Alexandre Béguyer de Chancourtois
'vis tellurique' (telluric screw)
The telluric screw plotted the atomic
weights of the elements on the outside of a
cylinder, so that one complete turn
corresponded to an atomic weight increase
of 16.
He was the first scientist to notice the
periodicity of elements. He devised a
three-dimensional arrangement of the
elements constituting an early form of
the periodic classification, published in
1862.
Döbereiner’s Triads
•
In 1817, a German chemist, Johann Dobereiner, observed that the atomic
weights of the alkaline earth metals formed a series, the atomic weight of
strontium being just midway between those of calcium and barium. He later
discovered other such triads, as well as triads in which the elements had similar
properties but almost identical atomic weights.
•
Limitations of Dobereiner's triads .
Dobereiner's triads convinced many chemists that atomic weight must
represent a fundamental characteristic of all elements. However,
Dobereiner could identify only three triads from the elements known at
that time. So, all the elements could not be arranged in triads.
Newlands’ Law of Octaves
•
•
•
John Newlands, an English
chemist, wrote a paper in 1863
which classified the 56 established
elements into 11 groups based on
similar physical properties.
In 1864 Newlands published his
version of the periodic table and
proposed the Law of Octaves (by
analogy with the seven intervals of
the musical scale).
This law stated that any given
element will exhibit analogous
behavior to the eighth element
following it in the table.
Mendeleev’s Periodic Table
•
•
•
In 1869 Dmitri Mendeleev (1834-1907) succeeded in organizing the 62
elements known at that time into a system of rows and columns on the
basis of increasing mass and similar chemical and physical properties.
Since the organization exhibited a periodic repetition of similar properties, it
became known as the Periodic Table of the Elements. It has become one of
modern chemistry's most useful resources.
Mendeleev predicted several new elements to complete the table.
Julius Lothar Meyer
• In 1890, working completely
independently, a few months
later, Meyer published a
revised and expanded version
of his 1864 table, virtually
identical to that published by
Mendeleev, and a paper
showing graphically the
periodicity of the elements as a
function of atomic weight.
Nomenclature for Groups
New IUPAC system
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Old IUPAC system (primarily in Europe)
IA
IIA
IIIA
IVA
VA
VIA
VIIA
VIIIA
VIIIA
VIIIA
IB
IIB
IIIB
IVB
VB
VIB
VIIB
CAS system (primarily in North
America) Chicago Academy of Science
IA
IIA
IIIB
IVB
VB
VIB
VIIB
VIII
VIII
VIII
IB
IIB
IIIA
IVA
VA
VIA
VIIA
VIIIA
VIII
Alternative
Periodic Tables
Adomah
Periodic Table
Paweł Najderek Periodic Table
Pyramidal Periodic Table
Mohammed Abubakr's circular periodic table
Stowe’s Periodic Table
3D Periodic Table
Extended Periodic Table
Los Alamos National Laboratory's Chemistry Division Presents a
Periodic Table of the Elements