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THE METALS

THE METALS.

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THE METALS

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  1. THE METALS The metals are the elements belonging to the first two groups of the periodic table. In particular we call “Alkaline Metals”  those metals belonging to the first group (except H); “Alkaline-Earth Metals” those belonging to the second group, and “Transition Metals” those which have either 1 or 2 valence electrons. At the same time as non-metals, they are classified according to their electronic structure, and so, not having too many valence electrons, they have the property to have low ionization potentials, low electronic affinities and poor electro negativity level.

  2. Metals often react spontaneously with water and acids and, being solids, they have a distinctive shine, and they are good heat and electric wires.  But the most important features are:  - TENACITY: capacity to endure mechanical stresses -         MALLEABILITY: capacity to let itself reduce in thin layers -         DUCTILITY: capacity to be bent easily -         HARDNESS: capacity to endure scratch and abrasions These features are justified by the type of  bond that put the atoms together: the atomic nucleuses are regularly set out in the crystal lattice, while the electron are able to move from a nucleus to another, without belonging to a determinate atom, creating the so-called “electronic cloud”; this electrons’ movement freedom justifies the electric and thermic conductibility of metals, while the compactness of the crystal lattice justifies their hardness.

  3. THE NON-METALS All non-metals haven’t got marked physical and chemical qualities. Are called “Non-Metals” all those metals that haven’t got the qualities common to all the metals et the elementary state. Non-metals at room temperature can be gaseous like nitrogen, oxygen, chlorine etc, or solid like silicon, carbon, sulphur etc; we can only find the bromine at the liquid state. However we can find physical and chemical qualities they share: Elevated electro negativity Their oxides, getting in touch with the water, turns into oxyacids In a aqueous solution tend to form anions They all are bad heap wires

  4. THE SEMIMETALS In the periodic table, between Metals and Non-Metals, there are the Semimetals, that make up the third group in which elements can be subdivided according to their physical and chemical qualities. Their properties are intermediate between those of metals, and those of non-metals, and they are situated on the big diagonal which divides elements according to the acid and basic characteristics of their oxides. The Semimetals gives rise to amphoteric oxides (like, for example, B2O3). The semimetals aren’t real electric conductors, but they’re semiconductors.

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