Fundamentals of Chemistry
THE PERIODIC TABLE
Most people are familiar with metals' physical properties. They are usually hard and
strong, capable of being shaped mechanically (malleable and ductile), and good
conductors of heat and electricity, and they have lustrous surfaces when clean. More
important for chemical classification are the chemical properties of metals because the
physical properties are not common to all metals. For example, mercury (Hg) is a
metal, although it is a liquid at room temperature, and sodium is a metal although it
is not at all hard or strong. Metals can be involved in a wide range of chemical
reactions. Their reactions with water range from violent with sodium and potassium
to imperceptible with gold and platinum. Metals are divided into the following two
The light metals, which are soft, have a low density, are very reactive
chemically, and are unsatisfactory as structural materials.
The transition metals, which are hard, have a high density, do not react
readily, and are useful structural materials.
The metals in Category 1 are located at the far left of the table (Groups IA and IIA).
The metals in Category 2 are located in the middle of the table (the B groups).
The nonmetals occupy the part of the periodic table to the right of the heavy, step-like
line. (refer to Figure 3 and Figure 4)
In general, the physical properties of the nonmetals are the opposite of those
attributed to metals. Nonmetals are often gases at room temperature. The nonmetals
that are solids are not lustrous, are not malleable or ductile, and are poor conductors
of heat and electricity. Some nonmetals are very reactive, but the nature of the
reactions is different from that of metals. Nonmetals tend to gain electrons to form
negative ions rather than to lose electrons to form positive ions.
The six elements in Group 0 represent a special subclass of nonmetals. They are all
very unreactive gases, so they are called the inert gases. For many years it was
believed that the inert gases would not and could not participate in chemical reactions.
In 1962, the first true compounds of an inert gas, XeF and XePtF , were positively
Since that time, several other compounds have been prepared. The preparation of
these compounds requires special conditions; under ordinary conditions, the inert
gases may be considered nonreactive.