JOURNAL #19
Who
is Mendeleev?
Who is Mosely?
How is the current periodic table
arranged?
ELECTRON CONFIGURATION AND
THE PERIODIC TABLE
THE PERIODIC TABLE
 Elements
are arranged vertically
into groups that share common
chemical properties.
 Elements are also organized
horizontally into rows, or periods.
 The elements on the left side of the
table (Groups 1 and 2) are reactive
metals
 The elements of group 1 are known
as the alkali metals.
ALKALI METALS
 In
pure state, all alkali metals have
a silvery appearance and are soft
enough to cut with a knife.
 They are very reactive and are not
found in nature as free elements
 They react vigorously with most
nonmetals
 They react strongly with water to
produce hydrogen gas and aqueous
solutions know as alkalis
ALKALINE-EARTH METALS
 The
elements of Group 2 are called
alkaline-earth metals.
 These metals are harder, denser and
stronger than the alkali metals.
 Alkaline-earth metals are also too
reactive to be found in nature as
pure elements.
TRANSITION ELEMENTS
 Transition
elements are metals with
typical metallic properties.
 They are good conductors of electricity and
have a high luster
 They are typically less reactive than the
alkali metals and the alkaline earth
metals.
 Some are so unreactive that they do not
easily form compounds, existing in nature
as free elements.
 Ex: Gold
MAIN-GROUP ELEMENTS
 Elements
of Groups 13-18 except
Helium are called main-group elements.
 The right end elements are nonmetals
(does not include Hydrogen and Helium)
 Metalloids: B, Si, Ge, Ar, Sb, Te
 Group 17 are known as halogens.
HALOGENS.
 Halogens
are the most reactive
nonmetals.
 They react vigorously with most metals
to form salts
 Fluorine and Chlorine are gases at room
temperature, Bromine is a reddish
liquid and Iodine is a purple solid.
Astitine is a synthetic element prepared
in small quantities.
METALLOIDS
 The
metalloids, or semiconducting
elements are located between nonmetals
and metals.
 They are mostly brittle solids with some
properties of metals and some of
nonmetals.
 The metalloid elements have electrical
conductivity intermediate between that
of metals and nonmetals.
 Metals
of the Main group elements are
generally harder and denser than the
alkaline earth metals, but softer and
less dense than the transition elements
 Lanthanides and Actinides are wedged
between groups 3 and 4 in the 6th and
7th periods.
 The actinides are all radioactive and
most are laboratory made elements.
 Elements found in group 18 are known
as noble gases.
LET’S REVIEW:
 What
is the name of the vertical
columns on the periodic table?
 What
is the name of the horizontal
rows on the periodic table?
LET’S REVIEW:
 What
is the name of the group 2
elements?
 What
is the name of the elements in
group 1?
LET’S REVIEW:
 What
is more reactive with
nonmetals: Alkali metals or alkalineearth metals?
 Are
transition elements metals or
nonmetals?
LET’S REVIEW:
 Group
 Are
7 elements are known as…?
transition elements metals or
nonmetals?