Transcript C3 Powerpoint Notes

Applied Chem. C3 Notes
Development of the Periodic Table
C3 Section 1 Vocabulary
• Periodicity
• Periodic Law
C3-1: Search for a Periodic Table
• 1829 JW Dobereiner (old German guy)
– Classified elements into 3 groups
• Triads
– Similar properties
Mendeleev’s Periodic Table
• 1869 Russian Chemist
• Studied properties of elements
• Arranged elements in repeating pattern of
increasing atomic mass
Mendeleev’s Table:
Why this Mendeleev’s table is special!
• Periodicity: Tendency to recur at regular
intervals.
• Mendeleev correctly predicted the properties
of several undiscovered elements.
• Left blank spaces for undiscovered elements
• Formed basis for modern periodic table
Modern Periodic Table
Characteristics of Modern PT
• Arranged by atomic number and not atomic
mass.
– Find where the atomic number increases but
atomic mass decreases.
• Periods (rows)
• Groups (columns)
Periodic Law
• Physical and chemical properties of the
elements repeat in a regular pattern when
they are arranged in order of increasing
atomic number
C3 Section 2 Vocabulary
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Period
Group
Noble Gas
Metal
Transition metal
Lanthanide
Actinide
Nonmetal
Metalloid
Semiconductor
C1 Section 2: Using the Periodic
Table
• Periods (rows)
– Represent the energy levels electrons can occupy.
– Each new period has a new energy level
• Groups (columns)
– Sometimes called a family
– All elements in a group have similar properties
Names of Groups
Physical States and Classes of
Elements
• Metals are elements that have luster, conduct
heat and electricity, and usually bend without
breaking
• Majority of elements
Where are metals located on
periodic table?
Transition metals
• Elements in groups 3-12
• Commonplace: Silver (Ag), Copper (Cu), Iron
(Fe), Zinc (Zn)
• Some radioactive
• Not as predictable in properties as main group
elements
Inner Transition Metals
• Lanthanides=Atomic numbers 57 (Lanthanum)
to 71.
– Not naturally abundant on earth
– Called “rare earth”
– All lanthanides have similar properties
• Actinides=Atomic numbers 90-103
– Unpredictable properties
Characteristics of Nonmetals
• Many nonmetals are abundant in nature.
• Examples include oxygen and nitrogen that
make of 99% of atmosphere.
• Don’t conduct electricity.
• Poor conductors of heat.
• Brittle when solid.
• Many nonmetals are gases at room
temperature.
Metalloids
• Some properties of metals and some
properties of nonmetals
• Lie between the border of metals and
nonmetals
• Some metalloids are semiconductors
• Silicon (Si), germanium (Ge) and arsenic (As)
are metalloids that are semiconductors.
• Look at your phone for uses of
semiconductors!
Electrical Conduction of
Semiconductor
Doped Semiconductors