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History of the periodic table . . . and my history with it

Dr. David Hobart on the history of the periodic table and his history with it
History of the periodic table . . . and my history with it

Dr. David Hobart

My assignment in inorganic chemistry class at Rollins College, Florida, in the late 1960s was to memorize the location of what were then the 104 known elements in the periodic table. I had no idea that in 2009 I would be lecturing on the periodic table before the Russian Academy of Sciences in Tobolsk, Siberia!

My fascination with the chemical elements began when I received a Gilbert chemistry set for Christmas when I was 10 years old. I enjoyed mixing concoctions of cobalt chloride and ferrous sulfate. In high school I was intrigued by the colors from various salts ionized by a Bunsen burner flame. In high school I took chemistry classes as electives and was inspired by a charismatic chemistry teacher who doubled as the school basketball coach.

My undergraduate career as a chemistry major was challenging but effective in part because I was in a class of four students. You couldn’t avoid getting called up to the chalkboard. Yes, we had chalkboards back then!

After a brief stint in the U.S. Air Force, I attended graduate school at the University of Tennessee, Knoxville. I was fortunate to perform my doctoral research at nearby Oak Ridge National Laboratory investigating unusual oxidation states of the actinide elements. Later, I became a staff scientist at Los Alamos and Lawrence Berkeley Laboratories, and a consultant for Sandia National Laboratories and DOE headquarters. During this time, I was also an adjunct professor of chemistry, lecturing students on many topics including the periodic table.

Evolution of the elements
The classic Greek periodic table included only four elements—earth, water, air, and fire. Gold, silver, copper, tin, lead, mercury, and others were known from antiquity.

  • 1817 — Bavarian chemist Johann Döbereiner developed the law of triads where, for example, lithium, sodium, and potassium displayed similar properties.
  • 1862 — French geologist Alexandre-Emile Béguyer de Chancourtois’ proposed a system ordered by increasing atomic weight and with similar elements lined up diagonally in a cylinder.
  • 1863 — English chemist John Newlands classified the elements into 11 groups, based on similar physical properties. He noted that there existed many pairs of elements, which differed by multiples of eight—the law of octaves.
  • 1869 — Russian scientist and educator Dmitri Mendeleev unveiled the hidden order of the natural world by developing the comprehensive periodic table—combining the law of triads, octaves, and diagonals. He surprisingly and boldly included "holes" in his table for as yet undiscovered elements and he even had the audacity to predict their properties!

Like my early love of chemistry, Mendeleev's table stood the test of time as new elements were discovered that fit the existing holes. In 2009, I was invited by the Russian Academy of Sciences to present a lecture and publish a paper for the 175th Anniversary of the birth of Dimitri Mendeleev in his birthplace, Tobolsk. My lecture paid tribute to Mendeleev and the significance of the periodic table I first discovered with my childhood Gilbert chemistry set. As the legendary physicist Richard Feynman put it, "If some universal catastrophe was to engulf the world and humankind could retain only one scientific concept to rebuild civilization, what would it be? The chemist’s answer is almost invariably the Periodic Table of the Elements."

-- David Hobart, Actinide Analytical Chemistry (C-AAC)

Visit the Los Alamos Periodic Table