The Periodic Table

1
The Periodic Table

• Pasterik
• 2006

2
Arranging the Elements

• system of classifying or logically grouping all
  of the known elements
• brings order to thousands of seemingly unrelated
  facts
• helped chemists predict the existence of elements
  that werent discovered yet
• groups elements according to their chemical and
  physical properties

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Developed by a Russian chemist named Dmitri
Mendeleev (duh-MEE-tree mehn-duh-LAY-uhf)

• Mendeleev used the following categories to
  organize his table
• chemical properties
• physical properties
• atomic mass
• density
• color
• melting point
• valence

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When arranged in order of atomic mass from
Lithium through Fluorine the pattern of valences
is 1 2 3 4 3 2 1 in each row of seven.
This is true for all of the elements in the
column.
Therefore the name periodic came about
the elements formed a definite repeating pattern,
very similar to a calendar.
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Because of this pattern he could make predictions
about elements which had not yet been
discovered.50 years later Henry Moseley
determined the atomic numbers for the elements.
Mendeleevs table was then rearranged into the
order it is today. -elements with similar
physical and chemical properties fall into place
without exception
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The Periodic Law

• The periodic law states that the physical and
  chemical properties of the elements are periodic
  functions of their atomic numbers.

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Design of the Periodic Table

• organizes information in a logical, usable, and
  meaningful way
• allows prediction of physical and chemical
  properties of an element by position
• can predict what other elements will react with a
  particular element
• arranged in columns and rows because of similar
  characteristics

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Columns in the Periodic Table

• vertical classification or groupings
• often referred to as families or groups
• each column is numbered 1-18 or Ia through VIII
• elements within the same family have similar
  properties

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Rows in the Periodic Table

• horizontal classification or groupings
• each row is called a period
• elements in a period are not alike in properties,
  properties change greatly across a given row
• the first element in a period is a very active
  metal
• the last element in most periods is a noble gas
• only seven periods

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Element Key

• Important information about an element is given
  in each square of the periodic table
• its atomic number
• chemical symbol
• element name
• Atomic mass

6CCarbon12.01
For example Carbon has an atomic number of 6
(or has 6 protons), an atomic mass of 12.01 and a
symbol of C
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Three main categories of elements on the Periodic
Table

• metals
• nonmetals
• metalloids

The 88 elements to the left side of the zigzag
line are metals or metal-like elements.
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Physical Properties of Metals

• luster (shininess)
• conductivity of heat and electricity
• high density
• high melting point
• ductility (they are ductile)
• malleability (they are malleable)

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Chemical Properties of Metals

• not easily observed
• 1, 2, 3, or 4 electrons in its outermost energy
  level
• tend to lose their electrons in a reaction
• easily susceptible to corrosion
• Corrosion is the gradual wearing away of metal
  due to a chemical reaction in which the metal
  element is changed into a metallic compound.

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Nonmetals

• located to the right of the zigzag line
• fewer nonmetals than metals

• in general, physical and chemical properties are
  
• opposite of metals

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Physical properties of nonmetals

• have no luster or are dull in appearance
• do not conduct heat and electricity well
• do not possess the properties of ductility or
  malleability
• lower density and lower melting point
• nonmetals can be very different, range from a gas
  to liquid to a solid
• can also be colored extremely different

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Chemical properties of nonmetals

• 5, 6, 7, or 8 electrons in the outermost energy
  level
• atoms with 5, 6, or 7 valence electrons gain 3,
  2, or 1 electron when they combine chemically
• elements with 8 electrons in their outermost
  shell tend to be non-reactive
• react mainly with metals

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Metalloids

• means metal-like
• include Boron, Silicon, Germanium, Arsenic,
  Antimony, Tellurium, Polonium and Astatine
• have some of the properties of metals and some of
  the properties of non metals
• are solids that are shiny or dull
• conduct heat and electricity but not as well as
  metals
• are ductile and malleable

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Chemical Families

• Vertical classification of elements or columns
• Elements within the same family of the periodic
  table have similar properties because they have
  the same number of valence electrons

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Ten major families

• 1. alkali metals2. alkaline earth metals3.
  transition elements4. boron family5. carbon
  family6. nitrogen family7. oxygen family8.
  halogen family9. noble gases10. rare earth
  metals

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Alkali Metals

• one electron in their outermost shell or one
  valence electron
• soft, silver-white, shiny metals
• bond readily with other substances
• never found uncombined in nature
• samples must be stored in oil to keep them from
  combining with water or oxygen
• most reactive metals

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Alkaline Earth Metals

• two valence electrons
• lose 2 electrons when combined with other
  substances
• never found uncombined in nature
• not quite as reactive as the alkali metals
• often mixed with other metals, such as aluminum,
  to form alloys of strong yet light in weight
  metals

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Transition Metals

• located between alkaline earth metals family and
  the boron family
• have similar properties to each other but
  different than other families
• most things we think of as metal are part of the
  transition metals

• good conductors of heat and electricity
• most have 1 or 2 valence electrons

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Boron Family -have 3 valance electrons

• Boron
• hard and brittle
• never found uncombined in nature
• found in borax
• used to make heat resistant glass

• 5
• BBoron10.81

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Boron Family

• Aluminum
• most abundant metal, 3rd most abundant metal in
  earths crust
• found in a mineral called bauxite
• extremely important metal for industry, light,
  strong and slow to corrode

13AlAluminum26.98
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Carbon Family

• have 4 valance electrons
• can either gain 4 electrons or lose 4 electrons
• includes Carbon (nonmetal), Silicon (metalloid),
  Germanium (metalloid), Tin (metal), and lead
  (metal)

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Nitrogen Family

• have 5 valence electrons
• tend to gain three electrons

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Oxygen Family

• have 6 valence electrons
• tend to gain 2 electrons

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Halogen Family

• have 7 valence electrons
• most active nonmetals
• never found free in nature
• react with the alkali metals quite easily
• when halogens react with metals they form
  compounds called salts
• Fluorine is the most active halogen

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The Noble Gases

• normally non-reactive
• also called inert
• all elements in this family are gases
• outermost electron shell is full
• found in small amounts in the earths atmosphere
  (less than 1)

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Rare-Earth Elements

• Located in the two rows at the bottom of the
  Periodic Table
• first row called the lanthanide series
• used to make glass alloys
• the second row called the actinide series -all
  actinides are radioactive