Dmitri Mendeleev

Chemistry professor who braved the ELEMENTS

The Russian revolutionary behind the ultimate symbol of science – the periodic table of elements.

By the way... My table was periodic, or repeating, because the properties of the elements I arranged followed a pattern.

St Petersburg University, where Mendeleev taught chemistry

Teacher’s textbook

Dmitri Mendeleev was born into a large Russian family in 1834. He studied science before becoming a chemistry professor at St Petersburg University in 1867. An entertaining LECTURER, he wrote his own chemistry textbook, entitled The Principles of Chemistry.

Who came before...

French chemist

The first list of chemical elements was compiled by French chemist

Antoine LAvoisier, who also identified and named oxygen in 1778 and hydrogen in 1783. In 1865, English chemist John newLAnds shared his Law of Octaves, according to which every eighth element behaved in a similar way when they were all arranged by the size of their atoms.

Chemical solitaire

While other scientists were trying to classify the 63 elements known at the time, Mendeleev is said to have devised a card classification game called CHEMICAL SOLITAIRE. He wrote each element’s name and symbol on a card and grouped the cards by how heavy each element was. This produced nine groups of elements that had similar properties.

engLish chemist

Grouping the elements by size led Mendeleev to publish the world’s first PERIODIC TABLE OF ELEMENTS in 1869. Clear and logical patterns could be seen in his arrangement. He even left empty spaces for undiscovered elements, which were later proven to be in the right place.

This early version of Mendeleev’s periodic table shows the elements that were missing.

Did you know? Known for his messy appearance, Mendeleev was said to work too hard to bother with getting his hair cut.

Later life

Mendeleev helped the Russian government build their first oil refinery in 1876. A lifetime believer in liberal causes, he resigned as professor in 1890 to support a student demonstration against government control. After his death in 1907, Mendeleev’s apartment was turned into a museum. In 1955, element 101 was named MENDELEVIUM to honour him.

Who came after ...

Each element has its own symbol, such as F for fluorine.

How he changed the world

By forming the periodic table, Mendeleev laid the foundations for modern chemistry. This at-a-glance guide to the atomic structures of elements remains the most important tool for scientists and students.

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In 1913, English physicist Henry MoSeley discovered a more accurate way to define elements, using their number of protons, rather than the entire mass.

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American chemist Glenn T SeaborG was the jointwinner of the Nobel Prize in Chemistry in 1951 for the identification of 10 radioactive elements.