The statement that is not correct for the periodic classification of element is (a) The properties of elements are the periodic functions of their atomic numbers(b) Non-metallic elements are lesser in number than metallic elements(c) The first ionisation energies of elements along a period do not vary in a regular manner with increase in atomic number(d) For transition elements the d-subshells are filled with electrons monotonically with increase in atomic number.
Answers
Answer:
(d) For transition elements the d-subshells are filled with electrons monotonically with increase in atomic number is the correct answer.
Explanation:
We'll check all options to get the correct answer.
(a) The properties of elements are the periodic functions of their atomic numbers
It is a correct statement.
This statement was given by the scientist Mosley.
He gave a form of modern periodic table which had atomic number as important.
(b) Non-metallic elements are lesser in number than metallic elements
This statement is correct.
The number of metals are more than number of nonmetals.
All the elements of s block f block and d block are metals.
(c) The first ionisation energies of elements along a period do not vary in a regular manner with increase in atomic number
This statement is also correct.
The first ionization enthalpy is not constant along a period.
It increases with the increase in atomoc number.
For example, Nitrogen has ionization energy more than oxygen.
(d) For transition elements the d-subshells are filled with electrons monotonically with increase in atomic number.
This statement is incorrect.
This trend is not true for elements like copper and Chromium.
The d subshells aren't filled monotonically.
There is a variation in the filling of orbitals.
Hence,
(d) For transition elements the d-subshells are filled with electrons monotonically with increase in atomic number is the correct answer
Answer:
d
Explanation:
for transition elements the 3d orbital are filled with electrons after 3p orbital and before 4s orbitals