Which of the following statements is/are true for the long form of the periodic table?

Options

A. it reflects the sequence of filling the electrons in the order of sub-energy level `s,p,d` and `f`
B. it helps to predict the stable valency states of the elements
C. it refelcts tends in physical and chemical properties of the elements
D. it helps to predict the relative ionicity of the bond between any two elements

Answer

B, C, D

Explanation

(a) Incorrect : Electrons are not filled in sub-energy levels `s,p,d` and `f` in the same sequence.
(b) Correct Number of valence shell electrons usually determine the stable valency state of an element.
(c) Correct : Physical and chemical properties of elements are periodic function of atomic number which is the basis of modern, long form of periodic table.
(d) Correct : Relative ionicity of the bond between any two elements is function of electronegativity difference of the bonded atoms whilch in turn has periodic trend in long form of periodic table.