The Amazing World of Chemistry

Gold, silver, copper these are the most common kind of metals.  Metal  is a solid material (an element, compound, or alloy) that is typically hard, shiny, and features good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible or it can be fused or melted. Metals are also ductile. It can be drawn out into a thin wire. Many elements and compounds that are not normally classified as metals become metallic under high pressures; these are known as metallic allotropes of nonmetals.

Metalloids are chemical element that has properties that are in between or a mixture of those of metals and nonmetals and is consequently difficult to classify unambiguously as either a metal or a nonmetal. There is no standard definition of a metalloid, nor is there agreement as to which elements are appropriately classified as such. In periodic table of elements, these are the alignments of the elements which are considered as Metalloids.

* The elements in pink color are considered as Metalloids. They are the: Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium and Astatine. *

Non-metals is a term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, every element in the periodic table can be termed either a metal or a nonmetal.

There is no rigorous definition for the term "nonmetal" – it covers a general spectrum of behavior. Common properties considered characteristic of a nonmetal include:

• poor conductors of heat and electricity when compared to metals
• they form acidic oxides
• in solid form, they are dull and brittle, rather than metals which are lustrous, ductile or malleable
• usually have lower densities than metals
• they have significantly lower melting points and boiling points than metals with the exception of carbon
• non-metals have high electronegativity

Only eighteen elements in the periodic table are generally considered nonmetals, compared to over eighty metals, but nonmetals make up most of the crust, atmosphere and oceans of the earth. Bulk tissues of living organisms are composed almost entirely of nonmetals. Most nonmetals are monatomic noble gases or form diatomic molecules in their elemental state, unlike metals which do not form molecules at all.