Presentation on theme: "The properties of Periodic table of elements.. Under normal conditions each atom is electrically neutral, since the number of electrons is equal to that."— Presentation transcript:
Under normal conditions each atom is electrically neutral, since the number of electrons is equal to that of neutrons.Is However, administration of energy, remove one or more electrons. The energy required by an atom to pull the outer electron of energy is defined first ionization. The energy required to remove a second electron is called the energy of second ionization. The atom formed after this process is called cation, or positive ion.
A + energia => A+ + e- The ionization is a periodic property.Furthermore as you can see how each period beginning with a low ionization and concludes with a noble gas at high ionization.Although energy is growing along the period, not growing so steadily, which is due to the increased amount of energy that needs a doublet compared to a separated electron.
From the table we see that the ionization energy increases along the period from left to right, but falls along the group progressing top to bottom. This trend is downwards due to the lower energy required to extract an electron that is in the outer energy levels are less attracted to the center. While,the upward trend to the right is due to the increased amount of energy, as is the larger the atomic weight and number of neutrons, then the electron will require more energy.
Another periodic property is electronic affinity. It represents the amount of energy transferred when an electron is acquired. A+e- => A- + energia Affinity for the electronics the same considerations of ionization.The electron purchased will fit in the outer level, so long the group will be less and less attracted, while a long period with the increase of nuclear charge will always be attracted. Therefore, the electronic affinity decreases along the group progressing from top to bottom, while increases over the period from left to right.
The ionization energy and electronic affinity are sizes that indicate the trend that each atom has to lose or acquire electrons.
These properties for a more immediate reading were linked together in a single property: the electronegativity. To measure this, Pauling proposed an arbitrary scale that assigns the highest value to Fluorine (4) and the lowest Cesium (0.7).
Electronegativities is the ability that the atom of an element to attract electrons, which agrees with the atom of another element when they are linked.
According to the new classification of the factors of a metal are those that have low ionization energy, electronic affinity and electronegativity.They are left or down the periodic table.
Another periodic property :The atomic radius.It is the distance between the core and outer electron and is measured namometers or angstrom
Proceeding along the group down there is an increase of atomic radius and volume.This is explained by falling into that group, increases the number of the quanto principale, increasing the total number of levels, so it is less the attraction towards the center.
While, over the period from right to left there is a reduction of the atomic radius.Infact over the period is an increase in the number of atoms and therefore protons for the same principal quantum number, and more attractive.
Work created by : Cirillo Michela, Loviglio Lucia, Mastrangelo Antonio, Moramarco Concetta, Storsillo Sabrina.