Dimitri Mendeleev's Periodic
Table of Elements
and Atomic Numbers
The Periodic Table based on the IOUPAC 1985 standard
Click on an Element in the Periodic
Table - More Information will be displayed under the table
Groups Properties within each individual group are similar, but
nevertheless vary within a group. Generally chemical activity
decreases as the period increases a non-metal group and increases
as the period increases within a metal group. The first element in
a group is always an active metal, the last is always an inactive
non-metal.
Periods The period of an element signifies the highest energy level an
electron in that element occupies in an unexcited state. Generally, within a given period, the chemical activity of
metals increases with the group number , while the chemical
activity of non-metals within a given period decreases with the
group number.
Dimitri Mendeleev
and the first Periodic Table
Dimitri
Mendeleev was born on February 7th 1834 in Tobolsk, a Town in Siberia.
In 1869 at the age of 35 the famous Russian Scientist perceived a
totally new classification Method "the periodic table", he
included all the 65 elements
known in his time by their atomic weights and chemical valency.
The Modern Periodic Table
Fifty years after Dimitri Mendeleev created the Periodic
cable, the British scientist Henry Moseley discovered that the
number of protons in the nucleus of a particular type of atom was
always the same. When atoms are arranged via their atomic number,
the few remaining problems with Mendeleev's original periodic
table disappeared. Due to Moseley's work, the modern periodic
table is based on the atomic numbers of the elements rather than
atomic mass.
ELEMENTS
MAP !
For additional information about the elements featured on the
Periodic Table please refer to our comprehensive
Elements Map!
Dimitri Mendeleev and The Periodic Table
The Elements are the building blocks of Modern Science and
Chemistry
