Alchemists in the Middle Ages first introduced symbols for elements, which influenced modern chemists' use of symbols for convenience. Jons Jacob Berzelius invented the current system of chemical symbols. Elements' symbols are derived from their names in Latin, English, or the scientists who discovered them. Henry Moseley's work with X-ray spectra showed that atomic number, not mass, determines an element's position in the periodic table. This led to restating the periodic law in terms of atomic number and the modern form of the periodic table.

2. ORIGIN OF THE CHEMICAL NAMES
AND SYMBOLS
• Alchemy refers to both an
early form of the
investigation of nature
and an early
philosophical and spiritual
disciplines. Alchemists
were known in different
aspects and one of these
is their popular culture,
the process of changing
some elements into gold.

3. • They were the first to introduce the symbols of the
elements in the Middle Ages. This practice of using
symbols has influenced modern chemists and helped
them to work easily with the elements.

4. • Modern chemists use
symbols for each
element to facilitate
writing and for
convenience. They
assigned each element
unique symbols. This
system of chemical
symbols was invented by
Jons Jacob Berzelius.

5. • Each element’s symbol has a different origin. Some of
the element’s symbol are either the initial letter of the
element or a combination of the first or another letter
from the Latin or English name of the elements.
SOME ELEMENTS WITH
SYMBOLS DERIVED FROM ITS
INITIAL LETTER
SOME ELEMENTS WITH
SYMBOLS DERIVED FROM THE
COMBINATION OF ITS FIRST AND
ANOTHER LETTER
SYMBOL NAME SYMBOL NAME
B BORON Br BROMINE
I IODINE Ir IRIDIUM
C CARBON Cl CHLORINE
H HYDROGEN He HELIUM
N NITROGEN Cr CHROMIUM
O OXYGEN Zn ZINC
K POTASSIUM (LATIN;
KALIUM)
Fe IRON (LATIN;
FERRUM)

6. • Aside from Latin and English names, some elements’ names
and symbols were derived from the scientists’ or discoverers’
names such as Bohrium (Bh) named after Neils Bohr and
Curium (Cu) for Marie Curie . Countries or places where it
was discovered (example, Californium derived from California,
mythology (example, Palladium derived from Pallas Athena),
planets (Plutonium from the planet Pluto, its Greek (like
Xenon, from the Greek word xenos; “foreign”) or German
names (like Zinc from German zinken, “point”), colors
(example Indium from the Greek word indium, “indigo”).
majority of the elements in the periodic table have symbols
consisting of two letters with the first letter capitalized. As
chemists discovered more elements, they began to observe
the arrangement of each element through patterns in their
properties. These patterns helped the chemists decipher the
elements better.

7. ORIGIN OF THE PERIODIC TABLE

8. ANTOINE LAVOISIER’S FIRST
CLASSIFICATION
• In 1789, Antoine Lavoisier,
a French physicist-chemist
published a book that
contained the classification
of elements based on their
similar properties. He
arranged the elements into
groups. Unfortunately, his
work did not progress until
his death in 1794.

9. DÖBEREINER’S TRIAD
• In 1817, Johannes Wolfgang
Döbereiner, a German chemist,
studied three elements and
noticed similarities among the
properties of metals such as Ca,
Ba and Sr. He continued to study
another group of three elements,
Cl, Br and I. Döbereiner
predicted that there is closeness
among the atomic masses
(traditionally called atomic
weight) of the said elements.

10. • He concluded that the atomic mass and the density of the
middle element in each triad is the approximate average if the
masses and densities of the first and the third elements.
Attempts were made to arrange the elements into triads in
1850. Nevertheless, more reliable measurements were
introduced and speculations on the atomic mass of the middle
element became less accurate.

11. DE CHANCOURTOIS’S TELLURIC HELIX
• In 1863, A.E. Beguyer de
Chancourtois had the idea
to plot the elements in a
spiral around the surface of
the cylinder divided into 16
vertical sections according to
the elements’ atomic
masses. In every vertical
strip, the elements with the
same physical and chemical
properties were grouped
together. He called his device
telluric helix.

12. • He stated from the results of his experiments that the
properties of elements were the same as the properties
of numbers. His idea seemed tenable enough at first but
failed to muster support.

13. NEWLANDS’ OCTAVES
• Although Döbereiner’s triads
proved to be significant and de
Chancortois idea did not gain
support at that time these were
used as bases for seeking
further classification of
elements. In 1869, John
Newlands, an English chemist
presented another way of
classifying elements.

14. • He arranged all the elements known at that time in
order of their atomic masses beginning with lithium
and noted that the eighth element has similar
properties to the first element, the ninth to the
second, and the tenth to the third and so on. He
compared their relationship to the octaves of musical
notes. He then called this pattern the Law of
Octaves.

15. MEDELEEV’S PERIODIC TABLE AND
MEYER’S PERIODIC PROPERTY GRAPH
• In 1869, Russian chemist Dmitri Ivanovich Medeleev and
German chemist Julius Lothar Meyer, working independently
presented closely identical version of arranging the elements
based on their increasing properties. Both scientists proposed
the periodic law which states that the properties of elements
are periodic functions of their atomic masses.
Dmitri Mendeleev Lothar Meyer

16. WILLIAM RAMSAY’S WORK ON NOBLE
GASES
• Between 1893 and 1898, Sir William Ramsay, John
Strutt or Lord Rayleigh and Morris Travers made a
research not related to the periodic table and worked
together to find out if there are unidentified elements
existing in the atmosphere.
Sir William Ramsay Morris Travers

17. • In 1894, Ramsay and Rayleigh isolated argon from
atmospheric nitrogen. Argon, the first noble gas, came from
the Greek work argos meaning “the lazy one” . In 1895,
Ramsay discovered the inert gas helium (derived from Greek
word helios, meaning sun). Later on, Ramsay and Travers
discovered more gases such as krypton (hidden), neon (new)
and xenon (stranger). Mendeleev added a new group to his
periodic table, the Group O or Group VIII for the group of
unreactive gases now called the noble gasses.

18. MOSELEY’S WORKS ON ATOMIC
NUMBERS
• In 1913, English physicist Henry
Moseley suggested that atomic
mass is not the property that
governs periodicity, a discovery he
got from his experiments on the X-
ray emission spectra. He observed
that the frequencies of X-ray
emitted from atoms of elements
were correlated with the sizes of
their nuclear charges. He assigned
a whole number to the size of the
nuclear charge of the atom and
called this atomic number.

19. • It was later proved that the atomic number was the
nuclear charge discovered by Ernest Rutherford. He
discovered that the atomic number differs from the
preceding element in the table. His work becomes a
significant discovery to the development of the periodic
table because he was able to solve the irregularities in
the Mendeleev’s periodic table.

20. • Moseley concluded that is its better to explain the trends
in Mendeleev’s table if the elements were arranged
according to increasing atomic number. The periodic
law was restated as “the properties of the elements
are periodic functions of their atomic numbers.”

21. THE MODERN PERIODIC TABLE
• By looking at the
periodic table, we can
see that the elements
are arranged
horizontally in the order
of increasing atomic
numbers. Each element
is identified by its
symbols placed at the
middle of the square;
the atomic number and
the atomic mass are
also included.

22. THE GROUPS
• The vertical columns are called groups or families. The
elements in each column have similar chemical
properties due to their similarities in the number of
electrons in their outer shells or in their highest principal
energy level. The periodic table has 18 vertical columns.
The elements in a group are also identified into two
categories such as Family A or the representative
elements and the Family B or the transition metals.

24. GROUP A OR FAMILY A
(REPRESENTATIVE ELEMENTS)
• Group IA – Alkali Metal
• Group II A – Alkaline Earth Metals
• Group IIIA – Aluminum Group/ Boron Family
• Group IVA – Carbon Family
• Group VA – Nitrogen Family
• Group VIA – Oxygen Family or Chalcogens
• Group VIIA – Halogens
• Group VIIIA – Group 0 or Noble/ Inert Gases

26. GROUP B OR FAMILY B (TRANSITION
ELEMENTS)
• Transition elements are found in between Group IIA and
Group IIIA and are referred to as the d-block while the
inner transition elements (lanthanides and actinides) are
found at the bottom of the table and are refered as the f-
block.

28. THE PERIODS
• Notice that the periodic table consists of several
horizontal rows called the periods or series. There are
seven periods which are designated as 1,2,3,4,5,6 and
7. the elements belonging to the same periods have
different properties.

30. • Period 1 has two elements (hydrogen and helium)
corresponding to the number of electrons in the s-
sublevel having their electrons occupying only one main
energy level.

31. • Periods 2 and 3 each has eight elements corresponding
to the eight electrons in the s and p block.

32. • Periods 4 and 5 each has eighteen elements
corresponding to the electrons in the s, p and d
sublevels

33. • The last two periods are called the inner transition
elements. The lanthanide series is then called the rare-
earth elements and the actinide series, the heavy rare
earth elements.

34. • Period 6 has 32 elements corresponding to the 32 electrons in the s,
p, d, and f sublevels. To make this period fit the 18-member
maximum arrangement of elements, the 14 elements from atomic
numbers 58 to 71 are removed and placed at the bottom of the table
to form the lanthanide series.

35. • Period 7 also includes 14 elements (from atomic number
90 through 103) which were placed at the bottom part of
the table to form the actinide series.

36. QUIZ: Identify the scientist who contributed the
following ideas in the development of the periodic table.
Choose your answers from the choices given on the right.
• Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley

37. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
1. He made a
device called a
telluric helix which
group elements
according to their
similar chemical
and physical
properties.

38. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
2. A French
physicist-chemist
who published a
book that
contained the
classification of
elements based
on their similar
properties.

39. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
3. He researched
on identifying
elements existing
in air which are
added in the
periodic table
grouped as noble
gases.

40. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
4. He grouped
elements in traids.

41. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
5. He formulated
the law of octaves.

42. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
5. He arranged
elements
according to
increasing atomic
weights.

43. • Antoine Lavoisier
• Johannes Döbereiner
• A.E. Beguyer de Chancourtois
• John Newlands
• Dmitri Mendeleev
• Lothar Meyer
• Sir William Ramsay
• Henry Moseley
6. He arranged
elements
according to
increasing atomic
number.