View full lesson: http://ed.ted.com/lessons/the-genius-of-mendeleev-s-periodic-table-lou-serico
The elements had been listed and carefully arranged before Dmitri Mendeleev. They had even been organized by similar properties before. So why is Mendeelev's periodic table the one that has endured? Lou Serico explains via eka-aluminum, an element whose existence Mendeelev predicted years before it was discovered.
Lesson by Lou Serico, animation by TED-Ed.