 Dmitri Mendeleev arranged the known elements by
characteristics. He summarized his findings in the
periodic law which states:
 When the elements are arranged in order of increasing
mass, certain sets of properties recur periodically.
 The elements are arranged in increasing order
according to atomic mass.
 They are arranged in rows and columns based on
characteristics of elements.
http://www.corrosionsource.com/handbook/periodic/periodic_table.gif
 Broadly elements can be divided into 3 groups
 Metals: good conductors of heat and electricity, they are
malleable (can be pounded into flat sheets), they are
ductile (can be drawn out into thin wires), shiny, lose
electrons, chemically reactive.
 Examples include chromium, copper, strontium, and lead
http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Graphics/MixedMetals(mayFranInt.).jpe
 Nonmetals: can be solids, liquids, or gases, poor
conductors of heat and electricity, gain electrons,
undergo chemical changes.
 Examples include oxygen, carbon, sulfur, and bromine
http://z.about.com/d/chemistry/1/0/X/6/graphite.jpg
http://www.amazingrust.com/Experiments/how_to/Images/Chlorine_gas.jpg
 Metalloids: show mixed properties between metals
and nonmetals. They are called semiconductors with
intermediate conductivity.
 Examples include silicon, arsenic, and antimony
http://www.mine-engineer.com/mining/mineral/Silicon.jpg
http://www.summagallicana.it/lessico/a/arsenic%20Jachymov.jpg
 The Metal, Metalloids, and Nonmetals are arranged in
particular portions of the Periodic Table.
 Each column of the Main group elements is called a
family or group. Each group has specific characteristics
 Noble gases- Group 8A Not reactive in most chemical
reactions, they are considered stable with no charge.
http://www.bbc.co.uk/schools/gcsebitesize/science/images/6_the_noble_gases.gif
 Alkali Metals- Group 1A are all reactive metals, Some are
explosive. Have a positive 1 charge.
http://www.bbc.co.uk/schools/gcsebitesize/science/images/periodictable_group1.jpg
 Alkaline earth metals- Group 2A- Also fairly reactive,
but not as reactive as the alkali metals. Have a 2+ charge.
http://images.google.com/imgres?imgurl=http://www.vectorsite.net/tpchem_eBe.png&imgrefurl=http://www.vectorsite.net/tpchem_05.html&usg=__bmu82B0xWcgEl4ies1I6V
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gbv%3D2%26tbs%3Disch:1
 Halogens- Group 7A Very reactive nonmetals. Have a
negative 1 charge as ions.
http://www.bbc.co.uk/schools/gcsebitesize/science/images/periodictable_group7.gif
 The transition metals are in the middle of the table
and have varying charges