Question

Which of the following statement(s) about the Modern periodic table is/are incorrect?
(i) The elements in the Modern periodic table are arranged on the basis of their decreasing atomic number.
(ii) The elements in the Modern periodic table are arranged on the basis of their increasing atomic number
(iii) Isotopes are placed in an adjoining group(s) in the periodic table.

• A. (i) only
• B. (i) and (ii)
• C. (ii) and (iii)
• D. (i) and (iii)

Answer 1

The correct option is D (i) and (iii)

The statements (i) and (iii) about the Modern periodic table are incorrect.
(i) The elements in the Modern periodic table are arranged on the basis of their increasing atomic number. Thus, $N(Z=7)$ is placed after $C(Z=6)$.

(iii) Isotopes are placed in the same group in the periodic table. Thus, $Cl-35$ and $Cl-37$ are present in the same group (group $17$).