Most nonmetals share the ability to gain electrons easily (i.e., they tend to form negative ions), but
otherwise they display a wide range of chemical behaviors and reactivities. The nonmetals are
located on the upper right side of the periodic table; they are separated from the metals by a line
cutting diagonally through the region of the periodic table containing elements with partially filled
p orbitals.
METALLOIDS
The metalloids, or semimetals, are found along the line between the metals and nonmetals in the
periodic table, and their properties vary considerably. Their densities, boiling points, and melting
points fluctuate widely. The electronegativities and ionization energies of metalloids lie between
those of metals and nonmetals; therefore, these elements possess characteristics of both those
classes. For example, silicon has a metallic luster, yet it is brittle and is not an efficient conductor.
The reactivity of metalloids is dependent upon the element with which they are reacting. For
example, boron (B) behaves as a nonmetal when reacting with sodium (Na) and as a metal when
reacting with fluorine (F). The elements classified as metalloids are boron, silicon, germanium,
arsenic, antimony, and tellurium.
DON’T MIX THESE UP ON TEST DAY
Metalloids
Boron (B)
Silicon (Si)
Germanium (Ge)
Arsenic (As)
Antimony (Sb)
Tellurium (Te)