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.
And when they were discovered, Mendeleev turned out to be right. For example, he predicted the properties of an undiscovered element that should fit below aluminium in his table. When this element, called gallium, was discovered in 1875, its properties were found to be close to Mendeleev's predictions.