Question

why did Mendeleev left some gaps in his periodic table?​

Answer 1

Answer:

Mendeleev left gaps in his periodic table because the properties of known elements predicted other, as-yet-undiscovered, elements in these locations. As Mendeleev organized his periodic table, he recognized that these gaps would be filled as future scientists identified new elements.

Answer 2

hey...he left some gaps because when he was arranging the elements ,the difference were very large so he thought there might be some other elements so he left the gaps for those elements ,later it was filled when new elements were discovered.