question_answer 79)

    Which of the following statement(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 number. (a) Only (i)                           (b) (i), (ii) and (iii)             (c) (i), (ii) and (iv)             (d) Only (iv)

Answer:

                  (b) Only statement 4 is correct. All the elements in the modern periodic table are arrange don the basis of their increasing atomic number. All the isotopes can be placed at one place in the same group of the periodic table.