D+Mendeleew

Dimitri Medeleev (1834-1907) According to pbs.org:**B  **orn in Siberia, the last of at least 14 children, Dmitri Mendeleev (1834-1907) revolutionized our understanding of the properties of atoms and created a table that probably adorns every chemistry classroom in the world. After his father went blind and could no longer support the family, Mendeleevís mother started a glass factory to help make ends meet. But just as Mendeleev was finishing high school, his father died and the glass factory burned down. With most of her other children now out on their own, his mother took her son to St. Petersburg, working tirelessly and successfully to get him into college.  In the late 1860s, Mendeleev began working on his great achievement: the periodic table of the elements. By arranging all of the 63 elements then known by their atomic weights, he managed to organize them into groups possessing similar properties. Where a gap existed in the table, he predicted a new element would one day be found and deduced its properties. And he was right. Three of those elements were found during his lifetimeógallium, scandium, and germanium. They provided the strongest support for his periodic table, a cornerstone both in chemistry and in our understanding of how the universe is put together.