history, development & periodic trends

• 1871 - mendeleev arranged the elements according to increasing atomic mass
• 1913 - moseley arranged the elements according to increasing atomic number
• moseley arranged the elements according to increasing atomic number with same properties in the same column
• mendeleev arranged the elements according to increasing atomic mass with same properties in the same row
• types of periodic trends

  1. atomic radius and ionic radius
  2. ionization energy
  3. electronegativity
  4. reactivity
  5. metallic character
• atomic radius - is a size of an atom
• when you go down a column, atomic radius increases
• when you go across a period, atomic radius decreases
• Ionic Radius - size of an atom when it is an ion.
• metals have more attraction
• nonmetals does not have more attraction
• Ionization Energy – energy needed to remove outermost e-
• Properties of a Metal –

  – Easy to shape

  – Conduct electricity and heat  

  – Shiny
• Alchemy refers to both an

  early form of the investigation of nature and an early philosophical and spiritual disciplines.
• Alchemists were known in different aspects and one of these is their popular culture, the process of changing

  some elements into gold.
• first to introduce the symbols of the elements in the Middle Ages.
• ANTOINE LAVOISIER'S FIRST

  CLASSIFICATION - In 1789, Antoine Lavoisier, published a book that contained the classification of elements based on their similar properties. He arranged the elements into groups.
• NEWLANDS' OCTAVES - In 1869, John Newlands, presented another way of classifying elements. He arranged all the elements known at that time in order of their atomic masses beginning with lithium, He then called this pattern the Law of Octaves.
• DE CHANCOURTOIS'S TELLURIC HELIX - In 1863, A.E. Beguyer de Chancourtois had the idea to plot the elements in a spiral around the surface of the cylinder divided into 16 vertical sections according to the elements' atomic masses. elements with the same physical and chemical properties were grouped together. He called his device telluric helix.
• MEDELEEV'S PERIODIC TABLE AND

  MEYER'S PERIODIC PROPERTY GRAPH - In 1869, Dmitri Ivanovich Medeleev and Julius Lothar Meyer, Both scientists proposed the periodic law
• WILLIAM RAMSAY'S WORK ON NOBLE

  GASES - Sir William Ramsay, John Strutt or Lord Rayleigh and Morris Travers made a research not related to the periodic table and worked together to find out if there are unidentified elements

  existing in the atmosphere.
• MOSELEY'S WORKS ON ATOMIC

  NUMBERS - Henry Moseley suggested that atomic mass is not the property that governs periodicity, a discovery he got from his experiments on the X- ray emission spectra. he called this atomic number.
• The vertical columns are called groups or families.
• Family B or the transition metals.
• GROUP A OR FAMILY A

  (REPRESENTATIVE ELEMENTS)

  • Group IA - Alkali Metal
  • Group II A - Alkaline Earth Metals
  • Group IlIA - Aluminum Group/ Boron Family
  • Group IVA - Carbon Family
  • Group VA - Nitrogen Family
  • Group VIA - Oxygen Family or Chalcogens
  • Group VIIA - Halogens
  • Group VIIIA - Group 0 or Noble/ Inert Gases
• horizontal rows called the periods or series.