Achievements of Mendeleev perodic law. Nine step eassy.
Answers
The achievements of Mendeleev's periodic table were:
Mendeleev kept some blank spaces in the periodic table for the elements that were yet to be discovered.
Predicted element
Actual element discovered later
Eka-boron
Scandium
Eka-aluminium
Gallium
Eka-silicon
Germanium
He also predicted properties of some elements even before their discovery and were later found to be correct.
Property
Eka-aluminium
Gallium
Atomic mass
68
69.7
Formula of oxide
E2O3
Ga2O3
Formula of chloride
ECl3
GaCl3
Mendeleev’s periodic table could accommodate noble gases when they were discovered.
(b) Mendeleev took the formulae of the oxides and hydrides formed by the elements as the basic properties of elements for their classification in the periodic table.