Download The Periodic Table

THE PERIODIC TABLE
HISTORY
• In 1869, Mendeleev studied
the 63 known elements.
• Mendeleev…
• grouped elements with similar
properties.
• arranged elements by
increasing atomic mass.
• detected patterns that led him
to develop the periodic table.
• Periodic means having a
regular, repeating pattern.
Dmitri Mendeleev
THE PERIODIC TABLE – PERIODS
Periods:
• Rows on the Periodic Table
• Elements in the same
period have the same
number of electron shells
(energy levels.)
•
•
•
•
First Period – K shell.
Second Period – K and L shells.
Third Period – K, L, and M Shells.
The periodic table includes 7 periods (largest atoms
contain 7 electron shells – K, L, M, N, O, P, and Q).
PERIODIC TABLE - GROUPS
• Groups (or families) are
columns on the
periodic table.
• Elements in the same
group or family have
similar properties.
• Elements in the same
group have the same
number of electrons in
their valence (outer)
shell.
CLASSES OF ELEMENTS - METALS
Metals
• Most of the
elements on the
periodic table are
metals.
• General Properties:
•
•
•
•
•
Solid
Shiny
Malleable
Ductile
Good conductors
of electricity
CLASSES OF ELEMENTS - NONMETALS
Nonmetals
• More than half of the
nonmetals are gases.
• General Properties:
• Not shiny (dull)
• Not malleable
(brittle)
• Not ductile
• Poor conductors of
electricity.
CLASSES OF ELEMENTS - METALLOIDS
Metalloids
• Also known as semiconductors.
• Smallest class of elements typically only 6 to 8 elements.
• Located on the Stair-Step on
periodic table.
• Stair-Step divides metals from
nonmetals.
• General Properties:
• Some properties of metals.
• Some properties of nonmetals.
READING THE PERIODIC TABLE
• Atomic Number:
number of protons in
atom
• Chemical Symbol:
One or two letters, the
first letter is capitalized
• Background color:
indicates metal, nonmetal, or metalloid
• Color of symbol:
indicates state (solid,
liquid, gas) of element
at room temperature
• Atomic Mass: average
mass number of all
isotopes of the
element.
Metals – Blue, Nonmetals – Yellow, Metalloids - Green