The Periodic Table
The Father of the Periodic Table—
Dimitri Mendeleev
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Mendeleev was the first scientist to notice
the relationship between the elements
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Arranged his periodic table by atomic mass
Said properties of unknown elements could be
predicted by the properties of elements around
the missing element
Moseley later discovered that the periodic
nature of the elements was associated with
atomic number, not atomic mass
Valence Electrons
Outermost (last shell) electrons in an
atom
 Electrons available for interactions with
valence electrons of other atoms in
chemical reactions
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Metalloid
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Six elements: Boron, Silicon, Germanium,
Arsenic, Antimony and Tellurium
Elements found along the stair-step line that
separates metals from non-metals.
Chemical elements with properties that are
in-between or a mixture of those of metals
and nonmetals
Have a metallic appearance but they are
brittle and only fair conductors of electricity
The Periodic Table
Column = Group or
Family
18 columns on the
Periodic Table
Row = Period
7 rows on the
Periodic Table
Hydrogen
Metals, Nonmetals, and
Semi-metals Nonmetals are on the
Only
nonmetal on the
metal side
Metals are to the
left of the
stair- step
Semi-metals,
“metalloids,”
touch the
stair-step
right of the stair-step
What is luster, malleable and
ductile?
•Luster describes the way a surface
reflects light…therefore metallic luster
would be shiny like a metal object.
•Malleable means to be able to press or
pound the substance into sheets or
different shapes.
•Ductile means that the substance can be
drawn out into thin wires.
The Groups of the Periodic Table
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Group 1: The Alkali Metals
Most reactive metals on the PT
 Reactive in water and air thus stored in oil
 Rarely found free in nature
 Charge of +1: 1 valence electron (1 electron
in the outer shell)
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The Groups of the Periodic Table
Group 2: The Alkaline Earth Metals
Still quite reactive
 React with water to form bases and
hydrogen gas
 Have a silvery luster
 Good conductors of heat and electricity
 Charge of +2: 2 valence electrons (2
electrons in outer shell)
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T he Groups of the Periodic Table
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Groups 3-12: Transition Metals
Found freely and in compounds in nature
 Great conductors of electricity
 Mixed with paints to achieve bright colors
 include radioactive elements 89 through 109
 include Mercury, the only metal that is liquid
at room temperature
 Have a silvery luster, except Copper and
Gold
 Charge is usually 2 but can vary—usually 2
valence electrons (2 in outer shell)
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T he Groups of the Periodic Table
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Group 13: Boron Family
Metallic (except Boron, which is a solid
metalloid)
 Scarce in nature (except Aluminum, which
is the most abundant metallic element
 Charge is +3: 3 valence electrons
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The Groups of the Periodic Table
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Group 14: The Carbon Family
Contains elements that can form unusual
bonds (Carbon and Silicon)
 Includes a nonmetal (Carbon), two
metalloids (Silicon and Germanium) and two
metals (Tin and Lead)
 Relatively unreactive
 Charge is +4 or -4: contains 4 valence
electrons
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T he Groups of the Periodic Table
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Group 15: The Nitrogen Family
Consists of two nonmetals (Nitrogen and
Phosphorus), two metalloids (Arsenic and
Antimony), and one metal (Bismuth)
 Nitrogen is most commonly found as
atmospheric gas
 Range from very abundant elements
(Nitrogen and Phosphorus) to relatively
rare elements (Arsenic, Antimony, and
Bismuth)
 Solids at room temperature, except
Nitrogen
 Charge is -3: contains 5 valence electrons
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The Groups of the Periodic Table
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Group 16: The Oxygen Family
 Consists of three nonmetals (Oxygen,
Sulfur, and Selenium), one metalloid
(Tellurium), and one metal (Polonium)
 Also known as the Chalcogens
 Charge is -2: 6 valence electrons
T he Groups of the Periodic Table
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Group 17: The Halogens
 Most reactive nonmetals, with Fluorine
being the most reactive of all nonmetals
 Found in the rocks of Earth's crust and
dissolved in sea water
 Exist as a gas at room temperature (F2 and
Cl2), a liquid (Br2), and a solid (I2 and At)
 Charge is -1: 7 valence electrons
T he Groups of the Periodic Table
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Group 18: The Noble Gases (The Inert Gases)
 Nonreactive
 Colorless gases
 Nonmetal
 Charge is 0: 2 or 8 valence electrons- have
a full outer energy level
Special Rows on the PT
Lanthanides
Actinides
Lanthanides Family
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Very reactive; burns easily in air
15 soft metals
Once called the Rare Earth Elements
Relatively abundant in Earth's crust
Found in Row 6 of the periodic table between
Groups 3 and 4
Occur together in nature, and they are very
difficult to separate from each other
Silvery-white metals that tarnish when
exposed to air, forming their oxides
Actinides Family
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All are radioactive.
15 very dense metals- tarnish in air.
Actinides combine directly with most
nonmetals