2.54. Groups with Metalloids http://www.ck12.org
FIGURE 2.113
The most common form of the metalloid
arsenic is gray and shiny. Arsenic is
extremely toxic, so it is used as rat poison.
Surprisingly, we need it (in tiny amounts)
for normal growth and a healthy nervous
system.Group 16: Oxygen Group
Group 16 of the periodic table is also called the oxygen group. The first three elements—oxygen (O), sulfur (S),
and selenium (Se)—are nonmetals. They are followed by tellurium (Te) (Figure2.114), a metalloid, and polonium
(Po), a metal. All group 16 elements have six valence electrons and are very reactive. Oxygen is a gas at room
temperature, and the other elements in the group are solids.
FIGURE 2.114
Tellurium is a silvery white, brittle met-
alloid. It is toxic and may cause birth
defects. Tellurium can conduct electricity
when exposed to light, so it is used to
make solar panels. It has several other
uses as well. For example, it makes steel
and copper easier to work with and lends
color to ceramics.Q:With six valence electrons, group 16 elements need to attract two electrons from another element to have a stable
electron arrangement of eight valence electrons. Which group of elements in the periodic table do you think might
form compounds with elements in group 16?
A:Group 2 elements, called the alkaline Earth metals, form compounds with elements in the oxygen group. That’s
because group 2 elements have two valence electrons that they are “eager” to give up. An example of a group 2 and
group 6 compound is calcium oxide (CaO).