The Periodic Table
Section 3
Section 3: Families of Elements
Preview
• Key Ideas
• Bellringer
• Classifying Elements Further
• Metals
• Nonmetals
• Semiconductors
The Periodic Table
Section 3
Key Ideas
〉What does each element family have in
common?
〉What are the families of metals?
〉What are some of the families of nonmetals?
〉What are semiconductors?
The Periodic Table
Section 3
Bellringer
Are you familiar with some of the elements on the periodic table? There
are probably many more elements that you have never heard of before.
You may be surprised to learn that even though you have never heard
of a certain element before, by looking at the periodic table, you can
guess some of the characteristics of that element. The periodic table
organizes elements into groups that have similar characteristics.
1. The elements below are classified as metals. You may be familiar
with some of these elements. If you know of a specific use for an
element listed below, write it down.
silver, Ag
lead, Pb
gold, Au
mercury, Hg
tin, Sn
aluminum, Al
copper, Cu
The Periodic Table
Section 3
Bellringer, continued
2. The elements below are classified as nonmetals. You may be
familiar with some of these elements. If you know of a specific
use for an element listed below, write it down.
helium, He
iodine, I
chlorine, Cl
neon, Ne
oxygen, O
carbon, C
3. Can you think of any characteristics that the metals have in
common? Do any of the metals have similar uses?
4. Look at the periodic table, and notice where each of the
elements listed in questions 1 and 2 is located. Where are the
metals located? Where are the nonmetals located?
The Periodic Table
Section 3
Classifying Elements Further
〉What does each element family have in
common?
〉In general, the elements in a family have the
same number of valence electrons.
The Periodic Table
Section 3
Metals
〉What are the families of metals?
〉Families of metals include the alkali metals, the
alkaline-earth metals, and the transition metals.
– alkali metal: one of the elements of Group 1 of the
periodic table
– alkaline-earth metal: one of the elements of Group 2 of
the periodic table
– transition metal: one of the metals that can use the inner
shell before using the outer shell to bond
The Periodic Table
Section 3
Metals, continued
• The alkali metals are very reactive.
– Alkali metals are in Group
1, on the left edge of the
periodic table.
– They are reactive
because they have one
valence electron that is
easily removed.
– They are soft and shiny,
and many have similar
melting points, boiling
points, and densities.
The Periodic Table
Section 3
Metals, continued
• Alkaline-earth metals form compounds that are
found in limestone and in the human body.
– Alkaline-earth metals are
in Group 2.
– Alkaline-earth metals are
less reactive than alkali
metals, but still react to
form positive ions.
– In general, alkaline-earth
metals are harder, denser,
stronger, and have higher
melting points than alkali
metals.
The Periodic Table
Section 3
Metals, continued
• Transition metals are in the middle of the
periodic table.
– With the exception of mercury, transition metals are
harder, more
dense, and have
higher melting
points than alkali
metals and
alkaline-earth
metals.
– They are also less
reactive, but they
can form positive
ions.
The Periodic Table
Section 3
Nonmetals
〉What are some of the families of nonmetals?
〉Families of nonmetals include the noble gases
and the halogens.
– noble gas: one of the elements of Group 18 of the
periodic table
– halogen: one of the elements of Group 17 of the
periodic table
The Periodic Table
Section 3
Nonmetals, continued
• The noble gases are relatively inert.
– The noble gases are in
Group 18.
– They exist as single
atoms instead of as
molecules.
– They are inert, or
unreactive, because
their s and p orbitals
are filled. In general,
they do not form ions
or compounds.
The Periodic Table
Section 3
Nonmetals, continued
• The halogens combine easily with metals to form
salts.
– The halogens are in
Group 17.
– With the addition of a
single electron,
halogens become
stable.
– They combine easily
with metals (especially
alkali metals) to form
salts.
The Periodic Table
Section 3
Nonmetals, continued
• Nonmetals and their compounds are plentiful on
Earth.
– Six other nonmetals
are on the right side of
the periodic table.
• Carbon can form many
compounds.
– There are millions of
carbon-containing
compounds.
The Periodic Table
Section 3
Semiconductors
〉What are semiconductors?
〉As their name suggests,
semiconductors are able to
conduct heat and electricity
under certain conditions.