Periodic Chart of Elements
Year of Discovery: 1880
What Is It? The first successful organizing system for the chemical elements
that compose Earth.
Who Discovered It? Dmitri Mendeleyev
Why Is This One of the 100 Greatest?
When most people think of the chemical elements, they picture Mendeleyev’s Periodic Chart of the Elements. This organizational table has served as the one accepted organizing system for the elements that make up our planet for 125 years. It is so important that
it is taught to every student in beginning chemistry classes. It led to the discovery of new elements and has been a cornerstone of chemists’ understanding of the properties and relationships of Earth’s elements. It has also helped in the design and conduct of chemical
experiments and greatly sped the development of science’s understanding of the basic
elements in the early twentieth century.
How Was It Discovered?
By 1867, 33-year-old Dmitri Mendeleyev had landed a position as chemistry professor
at St. Petersburg University—a remarkable accomplishment for the youngest of 14 children
of a Russian peasant. With an untamed thicket of hair, a wild, trailing beard, and dark, penetrating eyes, Mendeleyev was called “that wild Russian” by other chemi 7G2??WW&?R?????c??R&Vv?v?&???6?V?7G'?FW?F&???f?"??27GVFV?G2??F?RVW7F????Rf6VB??&Vv?????rF?R&???v2??rF?'&?vR?B?&v?RF?P?w&?v??r?7B?bc"???v?V?V?V?G26?F?B??27GVFV?G26?V?BV?FW'7F?BF?V?"6?&7FW&?7F?72?'?F??2F??R??V?FV?W?Wb?B6???V7FVB??&B?bFFg&????2?v?v?&???N( F??7F?( Fg&??F?Rv?&??b?F?W'2?W7V6???g&??F?RV?v?6?6?V?7G2?Wv??B?@??W?W'2?Bg&V?6???FR6??6?W'F??2???V?FV?W?Wb6?'FVBF?RV?V?V?G2'?F??2vV?v?C?'?f??&W6V?&??6S?'?F?Rv??F?W?F?N( F?"F?B??N( F6??&??Rv?F???G&?vV??6&&????B???vV??'?F?R???B?b6?G0?F?W?f?&?VC?'?v?WF?W"?V?V?V?BW??7FVB2v2??V?B??"6??C?'?v?WF?W"?V?V?V?@??2?&B?"6?gC?'?v?WF?W"?V?V?V?B?V?G2B??v??"??rFV?W&GW&S??B'?F?R6?P??bF?RV?V?V?N( ?27'?7F?2???F???r???vVB???F???R6V?6R?b??c"???v?V?V?V?G2??F?V??V?FV?W?Wb?6????VB?????W"?&V??VBF?BF?R??FW2?????&WVFVB@?&VwV?"??FW'f?2?WfW'?V?v?F??W?v2( ?2?( ??R&V??VBF?B??6V6??2???vfW2BF?P??? ???