State Mendeleev's periodic law. (a) What chemical properties of elements were used by Mendeleev in creating his periodic table? (b) State any three limitations of Mendeleev's classification of elements. (c) Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his periodic table ? Which group of elements was missing from Mendeleev's original periodic table?
ChemistryClass 10ICSEAnswered 27 Mar 2026
Answer
- The properties of elements are a periodic function of their atomic It was the discovery of atomic number which led to a change in Mendeleev's periodic law which was based on atomic mass.
- The elements having similar chemical properties form oxides and hydrides having similar Mendeleev used these properties for creating his periodic table.
- Limitations of Mendeleev’s classification of elements:
- Failed to explain the position of
- Wrong order of atomic masses of some elements could not be
- A position for hydrogen could not be assigned in the periodic
- Silicon and
- Noble gases were missing from Mendeleev's original periodic