Notes 6-1 “Development of the Modern Periodic Table”

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Notes 6-1 Development of the Modern Periodic
Table
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• I. History of the Periodic Tables Development
• A. It wasnt until 1860, when scientists
• agreed on how to determine the atomic
  
• mass, that organizing the elements
  began
• to take place.
• B. John Newlands
• a. first to organize elements according
• to increasing atomic masses.
• b. he noticed that their properties
• repeated every eighth
  element.

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• C. Meyer, Mendeleev and Moseley
• a. Mendeleev organized the first
• periodic table in 1864.
• b. he did so by arranging the elements
• in order of increasing atomic
  masses
• into columns with similar
  properties.
• c. his table was widely accepted b/c it
• predicted the existence and
  properties
• of undiscovered elements.
• d. once the atomic masses were more
• accurately measured, it was
  obvious
• several elements were out of
  place.

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• e. in 1913 Mosely arranged the
• elements by atomic number (
  of
• protons).
• f. this solved the problem of elements
• being out of place.
• II. The Modern Periodic Table
• A. There are 8(A) groups and 10(B) groups.
• B. The A groups are also called
• representative elements and the B
• groups are called transition
  elements.

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• C. There are 7 periods (or rows).
• D. 3 classifications for the elements metals,
• nonmetals, and metalloids.
• E. Metals are generally shiny, solids, good
• conductors of heat and electricity,
  most
• are ductile and malleable.
• F. Groups or families
• a. 1A alkali metals
• b. 2A alkaline earth metals
• c. 7A halogens
• d. 8A noble gases

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• G. Metals are located to the left of the stair
• stepping line while nonmetals are to
  the
• right.
• H. Nonmetals are in the upper right of the
• table.
• a. usually either gases or brittle dull
• looking solids.
• b. poor conductors of heat and
• electricity.

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• I. Metalloids are touching the stair stepping
• line.
• a. physical and chemical properties of
• both metals and nonmetals.