Modern periodic table

Assertion: Electron gain enthalpy always becomes less negative as we go down a group in Modern periodic table. Reason: The size of the atom increase on going down the group in Modern periodic table and the added electron would be farther from the nucleus.

Assertion: Electron gain enthalpy always becomes less negative as we go down a group in Modern periodic table. Reason: The size of the atom increase on going down the group in Modern periodic table and the added electron would be farther from the nucleus.

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 basiss of their increasing atomic mases. (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.

The group in the modern periode table, in which all the elements do not have same number of electrons in their valence shell is :