2.54 Groups with Metalloids http://www.ck12.org Contents
FIGURE 2.110
electrons. You can learn more about specific metalloids by clicking on the element symbols in the periodic table at
this URL: http://www.chemicool.com/.
Q:Why does the chemical behavior of an element depend on its number of valence electrons?
A:Valence electrons are the electrons in an atom’s outer energy level that may be involved in chemical reactions
with other atoms.
Group 13: Boron Group
Group 13 of the periodic table is also called the boron group because boron (B) is the first element at the top
of the group (seeFigure2.111). Boron is also the only metalloid in this group. The other four elements in the
group—aluminum (Al), gallium (Ga), indium (In), and thallium (Tl)—are all metals. Group 13 elements have three
valence electrons and are fairly reactive. All of them are solids at room temperature.
Group 14: Carbon Group
Group 14 of the periodic table is headed by the nonmetal carbon (C), so this group is also called the carbon group.
Carbon is followed by silicon (Si) and germanium (Ge) (Figure2.112), which are metalloids, and then by tin (Sn)
and lead (Pb), which are metals. Group 14 elements group have four valence electrons, so they generally aren’t very