Question

Given below is a part of the periodic table

H							He
Li	Be	B	C	N	O	F
Na
K
Rb
Cs

Arrange the given elements in the increasing order of the metallic character in the (i) Period (ii) Group

Answer 1

The periodic trend of the metallic character of across the period-

• Metallic character is measured by the ease of an element losing its valence electrons. Tendency to give away or lose its electron decreases from left to right because the atomic size decreases from left to right. Thus, Metallic character decreases on moving across a period.
• Period 1 has H and He. As we move from left to right, the metallic character decreases, so the increasing order of metallic character is He < H. Similarly, for period 2, the increasing order of metallic character is F <O < N < C < B < Be < Li

The periodic trend of the metallic character of across the group-

• Tendency to give away or lose its electron increases from top to bottom because as going down the size of atomic size increases and less attraction between nuclear charge and electrons. Thus, Metallic character increases on going down a group.
• For group 1, as the metallic character increases on moving down the group. Thus, the increasing order of metallic character is: H < Li < Na < K < Rb < Cs

Conclusion: Hence, considering trends of both periods and groups, the given elements are arranged in increasing order of metallic character as-

He < H < F < O < N < B < Be < Li < Na < K < Rb < Cs