Question

Which of the following statements (s) about the Modern Periodic table are incorrect?

(i) The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic numbers.

(ii) The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses.

(iii) Isotopes are placed in adjoining group (s) in the periodic table.

(iv) The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic numbers.

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

Answer 1

The correct option is B

(i), (ii) and (iii)

1. It is the atomic number and not the atomic mass that defines the most fundamental properties of the elements, this was discovered by Henry Mosley in the year 1913.
2. He modified the periodic law to "the physical and chemical properties of the elements are the periodic functions of their atomic numbers".
3. The modern periodic table was made based on this law, where the elements were arranged in the increasing order of atomic numbers.
4. Also, Isotopes are the elements having the same atomic number but different mass numbers, hence no special placement for isotopes is required.
5. Hence statements (a), (b), and (c) are incorrect and thereby option (b) is the correct option.

The correct option would be (B) and option (A), (C) and (D) are incorrect.