Dmitry Ivanovich Mendeleyev

Born in Siberia in 1834, Dmitri Mendeleev became one of the most influential chemists of the 19th century. He taught and wrote extensively, and he is remembered above all for arranging the known elements into a periodic system that revealed meaningful relationships between them.

What made his work so striking was not just the table itself, but the confidence with which he used it. Mendeleev left gaps for elements that had not yet been found and predicted their properties in advance, which helped convince other scientists that the pattern was real.

Alongside his work in chemistry, he wrote on a wide range of scientific and practical subjects, including measurements, industry, and education. He died in 1907, but his name remains closely tied to one of science's most powerful organizing ideas.