Respuesta :
Answer. The gaps on Mendeleev's table have never filled because those elements were not been discovered at that time.
Explanation:
- Mendeleev in his periodic table arranged the elements according to their atomic masses.
- During this process he encountered that there are missing gaps in his periodic table for which he though , that those missing elements belonging to that particular gap were have not been discovered at that time.
- He was able to calculate atomic masses of those undiscovered elements and on that basis he predicted their chemical properties and position of them in his periodic table. for example : prediction of gallium's atomic mass and its relative position in his periodic table which was not been discovered at that time.
