Question

Consider the following statements:
(a) The discovery of inert gases later on did not disturb Mendeleev's arrangement.
(b) In his classification of element, Mendeleev was guided proportional to two factors.
(c) In the present periodic table, periodicity in the properties of elements is related to the periodicity in their electronic configurations.

Which of the above statement(s) is/are correct?

• A. Only (a)
• B. Only (c)
• C. (a) and (b)
• D. (a), (b) and (c)

Answer 1

The correct option is D (a), (b) and (c)

a.) The discovery of inert gases, later on, did not disturb Mendeleev's arrangement as he made quite clear that the noble gas must reside in the periods of inert gases having their octet i.e.completely filled electrons in their valence shell.

b.) In the classification of elements, Mendeleev was guided proportional to by two factors which were their atomic masses and their chemical properties.

c.) In the present periodic table, periodicity in the properties of elements is related to the periodicity in their electronic configurations.

Hence it is (a), (b) and (c).