http://www.ck12.org Chapter 2. Matter
2.54 Groups with Metalloids
- Identify elements in groups 13–16 of the periodic table.
- List properties of a metalloid from each of these groups.
This image represents a famous ancient Egyptian named Tutankhamen. Do you see his heavy eyeliner? Most
likely the eyeliner was made of a mineral containing antimony. This metalloid was commonly used for makeup by
Egyptians between four and five thousand years ago. Today we know that antimony is toxic, although Tutankhamen
probably didn’t know that. Antimony is found in group 15 of the periodic table. Group 15 is one of four groups of
the periodic table that contain metalloids.
Groups 13–16
Groups 13–16 of the periodic table (orange in theFigure2.110) are the only groups that contain elements classified
as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13–16
contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or
both. Groups 13–16 fall between the transition metals (in groups 3–12) and the nonmetals called halogens (in group
17).
What Are Metalloids?
Metalloidsare the smallest class of elements, containing just six members: boron (B), silicon (Si), germanium
(Ge), arsenic (As), antimony (Sb), and tellurium (Te). Metalloids have some properties of metals (elements that can
conduct electricity) and some properties of nonmetals (elements that cannot conduct electricity). For example, most
metalloids can conduct electricity, but not as well as metals. Metalloids also tend to be shiny like metals, but brittle
like nonmetals. Chemically, metalloids may behave like metals or nonmetals, depending on their number of valence