periodic table

• Johan Wolfgang Dobereiner


  German chemist who formed the triads of elements with similar properties
• John Newlands


  English chemist who proposed the Law of Octaves
• Julius Lothar Meyer


  German chemist who arranged the elements in order of increasing atomic mass
• Dmitri Ivanovich Mendeleev


  Russian chemist who arranged the elements in order of increasing atomic mass
• Henry Moseley


  English physicist who found that the frequencies emitted by elements follows the ordering of the elements by atomic number
• Modern Periodic Table Law states that the properties of elements vary periodically with atomic number
• Groups


  Vertical columns of the periodic table, identify the principal families of elements (18 groups)
• Periods


  Horizontal rows of the periodic table
• Main Group of Representative Elements

  • Elements from taller columns (Groups 1,2 and 13-18)
• Group 1 or Family IA

  • Alkali metals
• Group 2 or Family A

  • Alkaline earth metals
• Group 13


  • Boron Group
• Group 14


  • Carbon Group
• Group 15


  • Nitrogen Group
• Group 16


  • Oxygen Group
• Group 17 or Family VIIA

  • Halogens
• Group 18


  • Noble or Inert gases
• Transition Metals


  Group 3 to 12
• Special series of Elements

  • Lanthanides - "rare-earth metals"
  • Actinides - radioactive elements
• Classification of Elements


  • Metals - left side
  • Non-metals - right side
  • Semimetals or Metalloids - zigzag line