Types of Elements

The elements of the periodic table may be classified into three categories: metals, located on the
left side and in the middle of the periodic table; nonmetals, located on the right side of the table;
and metalloids (semimetals), found along a diagonal line between the other two.

METALS

Metals are shiny solids at room temperature (except for mercury, which is a liquid), and generally
have high melting points and densities. Metals have the characteristic ability to be deformed
without breaking. The ability of a metal to be hammered into shapes is called malleability and the
ability to be drawn into wires is called ductility. Many of the characteristic properties of metals,
such as large atomic radius, low ionization energy, and low electronegativity, are due to the fact
that the few electrons in the valence shell of a metal atom can easily be removed. Because the
valence electrons can move freely, metals are good conductors of heat and electricity. Groups IA and
IIA represent the most reactive metals. The transition elements are metals that have partially filled d
orbitals.

NONMETALS

Nonmetals are generally brittle in the solid state and show little or no metallic luster. They have high
ionization energies and electronegativities, and are usually poor conductors of heat and electricity.