Download INTRODUCTION The present modern periodic table explains in

INTRODUCTION
The present modern periodic table
explains in detail and updated the
properties of chemical elements
based on their atomic structure
.According its chemical properties,
elements are classified as metals and
non-metals.
There are more than non-metallic
metals. The same elements that are
in earth exist on other planets from
outer space. The student must know
both classes, their physical properties
and
important
chemical;
not
memorize, but familiar, so for
example familiar with the valence of
the main metallic and nonmetallic
elements, not individually or in
isolation, but by groups or families (I,
II, III, etc.) and thereby learn easy and
flexible formulas and names of
chemical compounds, which is a vital
part of the chemical language
PERIODIC TABLE OF THE
ELEMENTS
The periodic table of elements
classifies, organizes and distributes
the various chemical elements
according to their properties and
characteristics; its main function is to
establish a specific order grouping
elements. Usually attributed to Dmitri
Mendeleev table who ordered the
items based on their chemical
properties, although Julius Lothar
Meyer, working separately, conducted
a system from the physical properties
of atoms. The current structure was
designed by Alfred Werner from the
version of Mendeleev. In 1952, the
Costa Rican scientist Chaverri Gil
(1921-2005) presented a new version
based on the electronic structure of
the elements version, which places
the lanthanide and actinide series in a
logical sequence according to their
atomic number.
The evolution of the classification of
the elements has its main location
moments groups of elements such as:
Act 1829 Duberiener triads (groups of
three elements with similar behavior)
Act 1864 Newlands octaves (Groups
of eight elements with similar
behavior)
1869 Act periodic Mendeleev and
Meyer (Order by increasing atomic
mass)
Moseley Act 1913 (Order by
increasing atomic numbers) At
present an atomic orbital is described
by a particular permitted set of
quantum and level values, shape and
orientation, two electrons can occupy
the same orbital only if their spins are
opposite; in this case it is said that
electrons are mismatched when
occupying a single orbital or paired,
when both occupy the same but with
opposite spin orbital. For the first level
there is only a maximum atomic
orbital 1s and may have two electrons
thus defining configurations for
hydrogen 1s 1 and for helium 1s2,
also electronic sequence that predicts
the start of construction (Aufbaud) are
built where the shape of fill levels and
sublevels is defined as the energy as
shown below:
• Up and to the right increases the
ionization energy, electron affinity and
electronegativity.
Some groups are better known by
their specific name as:
Group 1: Alkali metals
Structure and organization of the
periodic table
The present periodic table is a system
where the elements are sorted known
to date.
• They are placed from left to right
and top to bottom in order of
increasing atomic numbers. The
elements are arranged in seven rows
• Horizontal called periods, and in 18
vertical columns called groups or
families.
• Down and to the left increases the
atomic radius and ionic radius.
Group 2: alkaline earth metals
Group 14 the carbonoideos
Group 15 the nitrogenoideos
Group 16 the anfigenos
Group 17 halogens
Group 18: the noble gases
Periodic properties
Many physical properties such as
melting point, boiling point and atomic
sizes
show periodic
variations
according to the period (level) and the
group they belong to the elements
and knowledge to predict chemical
behavior.
Atomic
Radius:
Atomic
radii
decrease from left to right in groups
and decrease in low-up periods.
Ionization energy: is the amount of
energy required to remove an
electron less attracted to the nucleus
in an atom is called the ground state
and first ionization energy.
The electron affinity: is the amount
of energy required to add an electron
to an isolated gaseous atom to form
an anion (negatively charged ion).
The ionic radius: Ions formed either
losing electrons (to overcome the
ionization energy) or gain electrons
(to overcome the electron affinity).
The general trend of the ionic radii is
increased from left to right in the
period and up and down the groups.
Electronegativity: the tendency of an
atom to attract electrons when it
combines chemically with other
atoms.
Melting item: The periodic behavior
of the melting item has a tendency to
increase during periods of increased
left to right and from bottom to top in
the groups. External transition for a
tendency to reduce its melting point in
the periods from left to right and
increase in the groups; in the inner
transition elements
values are
consistent trend.
Boiling item: for the representative
elements there is a tendency to
increase from bottom to top in IA, IIA,
IIIA and IVA groups. The elements of
internal and external transition there
is a tendency to reduce the boiling
point periods and increase with level.
CONCLUSION
From the periodic table of the
chemical
element
necessary
information is obtained, as regards its
internal structure and properties,
either physical or chemical.
The periodic table was designed so
that the elements that share similar
properties are arranged in a column
named group. This facilitates the
study and comparison of the different
elements.
BIBLIOGRAPHY
http://www.monografias.com/trabajos
68/tabla-periodica/tablaperiodica3.shtml
http://www.angelfire.com/biz/diegolim/
quimica.html
http://es.wikipedia.org/wiki/Tabla_peri
%C3%B3dica_de_los_elementos