In 1869, the Russian chemist Dmitri Mendeleev published his periodic table, arranging the known elements primarily by atomic weight.
Tellurium (Te\text{Te}Te) has an atomic weight of 127.6, and iodine (I\text{I}I) has an atomic weight of 126.9. Explain why Mendeleev switched the order of these two elements, placing tellurium before iodine.
Mendeleev deliberately left gaps in his table and made detailed predictions about the elements that would fill them. Explain how these predictions led to the widespread acceptance of his periodic table by the scientific community.
Identify the fundamental property of atoms that is used to sequence elements in the modern periodic table, which resolved anomalies such as the tellurium-iodine pair.