Non-mosaic Down syndrome is a genetic disorder. Most people with non-mosaic Down syndrome have three copies of chromosome 21 in all of their cells (chromosome 21 trisomy); some have an extra copy of chromosome 21 attached to a different chromosome in all of their cells (chromosome 21 translocation).
Making the world better, one answer at a time. Stanislao Cannizzaro, an Italian chemist who worked with Dmitri, inspired Dmitri Mendeleev to come up with his creative ideas. Atomic Weight also inspired Mendeleev.
The greatness of Mendeleev was that not only did he leave spaces for elements that were not yet discovered but he predicted properties of five of these elements and their compounds. How foolish he would have seemed if these predictions had been incorrect but fortunately for him three of these missing elements were discovered by others within 15 years (ie within his lifetime).