Mendeleev And The Periodic Table Flashcards
Early chemists background
In the 1800 only 60 elements had been discovered. Scientists did not know about proton number and subatomic particles. They assumed all of them had been discovered and organized elements by order of atomic weight.
The problems they faced
Some elements were placed in groups with other elements which did not have similar chemical properties
How did Mendeleev overcome some of the problems
He organized them by atomic eight but left space for other elements as he knew not all of them had been discovered. He was able to predict the properties of those elements. However he did revered the atomic weight of Te and I so their properties matched the rest of the group.
How was Mendeleev proved right ?
He managed to predict the properties of missing elements like Gallium which were later discovered and filled the empty spaces. The properties also matched his descriptions.
