Question

Mendeleev’s periodic law states that the properties of elements are a periodic function of their:
(A) Reactivity of elements
(B) Atomic size
(C) Atomic mass
(D) Electronic configuration

Answer 1

Hint: The elements in the Mendeleev periodic table are arranged by their periodic properties, which are repeated trends of physical and chemical characteristics of the elements. We can observe the trends by just examining the periodic table carefully.

Complete step by step solution:
-Mendeleev and Meyer independently came out with their individual periodic law.
-Mendeleev a scientist prepared the periodic table basing on their atomic mass and said that few properties of the elements will reoccur.
-Mendeleev’s periodic law states that the properties of the elements are a periodic function of their atomic masses.
-That means the elements are arranged in the periodic table according to their increasing order in atomic masses, and elements with similar physical and chemical properties are recurrent after some steady interval in the periodic table.
-Therefore Mendeleev’s periodic law states that the properties of elements are a periodic function of their atomic masses.

So, the correct option is (C).

Note: In Mendeleev’s periodic table the elements with the same features come in vertical columns called groups. The molar mass of the elements also increases from top to bottom in groups. Mendeleev’s did not predict the noble gases and left no space for them. Mendeleev's periodic table is worth mentioning because it displays mostly correct values for atomic mass and contains some blank spaces for a few unknown elements.