State Mendeleev’s periodic law.

In Mendeleev’s periodic table, why was there no mention of noble gases like helium, neon and argon?

Would you place the two isotopes of chlorine, C1-35 and C1-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.

What chemical properties of elements were used by Mendeleev in creating his periodic table ?

State any three limitations of Mendeleev’s classification of element.