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History of the
Periodic Table
The modern periodic table is the result of the
work of many scientists over the centuries
who studied elements and discovered
periodic patterns in their properties.
6
1940
Synthesized elements with
an atomic number larger than 92
become part of a new block of the
periodic table called the actinides.
5
1913
Henry Moseley determines
the atomic number of known
elements and establishes that
element properties vary
periodically with atomic number.
4
1894-1900
The noble gases—
argon, helium, krypton, neon,
xenon, and radon—become a new
group in the periodic table.
1
1789
Antoine Lavoisier defines
the chemical element, develops a
list of all known elements, and
distinguishes between metals
and nonmetals.
2
1814
An academic journal
publishes Jons Jacob Berzelius's
paper proposing letter symbols for
the known elements.
3
1869
Lothar Meyer and Dmitri
Mendeleev independently develop
tables based on element
characteristics and predict the
properties of unknown elements.
7
1969
Researchers at the
University of California, Berkeley
synthesize the first element
heavier than the actinides. It has
a half-life of 4.7 seconds and is
named rutherfordium.
8
2016
The syntheses of elements
113, 115, 117, and 118 are confirmed.
This completes the seventh period
of the periodic table.
Figure 10
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Module 5 • The Periodic Table and Periodic Law