2. Father God,
Come with us today.
Fill our hearts with joy.
Fill our minds with learning.
Fill our classroom with peace.
Fill our lesson with fun.
Fill our friendships with
kindness.
Fill our school with love.
Amen.
20. History of the Periodic Table
Aristotle ~330 B.C.
• Four element theory:
– Earth, Fire, Water, Air
21. History of the Periodic Table
Antoine Lavoisier
~1770-1789
• Wrote the first list of
elements containing 33
elements
• Distinguished between
metals and non-metals
22. History of the Periodic Table
Jons Jakob
Berzelius~ 1828
• Developed a table
of atomic weights
• Introduced letters
to symbolize
elements
23. History of the Periodic Table
Johann Döbereiner ~ 1817
• German chemist who made the
first attempt to group known
elements with similar properties.
• He was able to form groups of 3
elements with similar properties
which he called triads.
Examples of Dobereiner’s
triads are Li Na K, Cl Br,
Ca Sr Ba.
25. History of the Periodic Table
John Newlands ~1863
• English scientist who made the next
attempt to classify the 56 known
elements during his time.
• He found out that when elements are
arranged in order of increasing atomic
mass, every 8th element has properties
similar to the first like the Octaves in
music wherein notes are repeated for
every 8th note. He called this the Law of
Octaves.
26. History of the Periodic Table
Law of Octaves
However, this law is applicable only up
to Calcium, the next elements after this,
did not show similar pattern.
27. History of the Periodic Table
Lothar Meyer ~1869
• Compiled a Periodic
Table of 56 elements
based on the
periodicity of properties
such as molar volume
when arranged in order
of atomic weight
28. History of the Periodic Table
Dmitri Mendeleev ~ 1869
• a Russian chemist who first
succeeded in developing a workable
Periodic Table
• He examined the relationship between
the atomic mass of elements and their
properties and believed that the
atomic mass was the fundamental
property in classifying elements.
29. History of the Periodic Table
Dmitri Mendeleev ~ 1869
• He then arranged the elements in order of increasing
atomic mass in tabular form placing elements with
similar properties in the same vertical column and left
blank spaces reserved for elements that are yet to be
discovered. Thus, developed the first Periodic Table.
• He also proposed the Periodic Law which states that
the physical and chemical properties of elements are
periodic functions of their atomic masses.
30.
31. History of the Periodic Table
Demerits of Mendeleev Periodic Table
• He was unable to locate hydrogen in the periodic
table.
• Increase in atomic mass was not regular while
moving from one element to another. Hence, the
number of elements yet to be discovered was not
predictable.
• Later on, isotopes of elements were found which
violated Mendeleev’s periodic law
32. History of the Periodic Table
William Ramsay
~1894
• Discovered the Noble
Gases
33. History of the Periodic Table
Henry Moseley ~1913
• An English physicist who discovered that atomic number of
an element which is equal to the number of protons is the
fundamental property that determines the properties of
elements.
• This prompted him to arrange the elements in the Periodic
Table in order of increasing atomic number.
• He also revised Mendeleev’s Periodic Law by stating that
the properties of elements are periodic functions of their
atomic number. Consequently, his work corrected the errors
or irregularities noted in Mendeleev’ Periodic Table.
34. History of the Periodic Table
Glenn Seaborg ~1940
• Discover transuranium elements
• Responsible for the identification of
more than 100 isotopes of elements
throughout the Periodic Table.
• He placed the first 14 elements heavier
than actinium in the periodic table of
elements as a 5f transition series under
the lanthanide 4f transition series.
35. Have you ever experience
travelling to a new place for
the first time?
36. How did you able to locate
that certain place when you
still have no idea where it is?
37. What do you think is the
importance of the periodic
table?
38.
39.
40.
41. Let’s turn back the hands of time. Imagine yourself as a
columnist in Manila Bulletin Today. During the time of
Dmitri Mendeleev or Henry Moseley, you were assigned
to write an article about these scientists. Choose only
one scientist and write one or two paragraph article
about their accomplishments related to the
development of Periodic Table. You will be graded
based on the following rubric.
