Question

The properties of elements are periodic function of thier atomic number.justify(5).

Answer 1

This statement means that when elements are arranged in increasing order of their atomic numbers, similarities in properties of the elements appear at regular intervals. For example: The electronic configuration of the elements repeats itself after a regular interval and thus elements with same electronic configuration are grouped in the same group. In a group, the elements have same number of valence electrons and thus similar chemical properties.The elements in group I are strongly metallic and electropositive as they form monovalent ions such as Na+, Li+, K+ etc. readily. Similarly, elements of group 17 have 7 valence electrons and are highly reactive.