Dmitry Ivanovich Mendeleyev

(1834-1907)

Dmitry Ivanovich Mendeleyev was Russian chemist, known

for his development of the periodic table of elements. This is a

table created to arrange the elements by their atomic number.

Mendeleyev was born in Tobolsk, Siberia. He studied

chemistry at the University of Saint Petersburg, until 1859 when

he was sent to learn at the University of Heidelberg. Where he

became aquatinted with the Italian chemist Stanislao

Cannizzaro, whose views on atomic weight changed his thinking.

Mendeleyev came back to Saint Petersburg and became a

professor of chemistry at the Tech. Institute in 1863. He

became professor of general chemistry at the University of

Saint Petersburg in 1866. Mendeleyev was a renowned teacher,

and, because no good textbook in chemistry was available, he

wrote the two-volume "Principles of Chemistry" which became a

classic.

During the writing of his book, Mendeleyev tried to

organize the elements according to their chemical properties and

atomic mass. In 1869 he published his first of what became

known as the periodic table, a table created to arrange the

elements by their atomic number. In 1871 he published a better

version of the periodic table, in which he left empty spaces for

elements that were undiscovered. Mendeleyev's chart and

theories gained acceptance when three predicted

elements-¯gallium, germanium, and scandium-¯were discovered

and fit the places he had set aside.

Mendeleyev's experiment also included the study of the

"chemical theory of solution", the "thermal expansion of liquids",

and the "nature of petroleum. In 1887 he went on a solo balloon

flight to study a solar eclipse, being the first to ever witness a

solar eclipse from the air. In 1893 he became director of the

Bureau of Weights and Measures in Saint Petersburg and held

this position until his death.