http://www.ck12.org Chapter 6. The Periodic Table
FIGURE 6.1
Dates of discovery of the chemical ele-
ments.FIGURE 6.2
The elements chlorine, bromine, and io-
dine: chlorine is a greenish-yellow gas,
bromine is a dark orange liquid, and io-
dine is a shiny blue-black solid. Though
different in appearance, they have very
similar chemical properties.that every eighth element exhibited similar properties. He called this relationship theLaw of Octaves. Unfortunately,
some elements were missing, and the law did not seem to hold for elements that were heavier than calcium.
Newlands’ work was largely ignored and even ridiculed by the scientific community in his day. It was not until
years later that another more extensive effort to construct a periodic table would gain much greater acceptance, and
the pioneering work of John Newlands would be appreciated.
Mendeleev’s Periodic Table
In 1869, Russian chemist and teacher Dmitri Mendeleev (1836-1907) published a periodic table of the elements. The
following year, German chemist Lothar Meyer independently published a very similar table. Mendeleev is generally
given more credit than Meyer because his table was published first and because of several key insights that he made