Question

In the periodic table, the metallic character of the element:
A. Decreases from left to right across a period and on descending a group
B. Decreases from left to right across a period and increases on descending a group
C. Increases from left to right across a period and on descending a group
D. Increases from left to right across a period and decreases on descending a group

Answer 1

Hint: Metals are present on the left side of the periodic table and non-metals are present on the right side of the periodic table. Metallic character depends on the ability of the element to lose the electron. Moving down the group ability of elements to lose the electron increases.

Complete answer:
- As we move from left to right across the period atomic size decreases as the new electron is added to the same shell. Due to a decrease in atomic size and increase in the number of valence electrons, the tendency of elements to lose the outermost valence electron decreases across the period from left to right.
- Metallic character depends on the ability of the element to lose the valence electron. Due to a decrease in the ability of an element to lose valence electrons from left to right across a period, metallic character decreases across a period from left to right.
- As we move down the group from top to bottom atomic size increases as new electrons get added to the new shell. Due to an increase in atomic size down the group, the tendency of the element to lose the outermost valence electron increases down the group and thus metallic character increases as we move from top to bottom down the group.
- Thus, the metallic character decreases from left to right across a period and increases on descending a group.

Hence, the correct option is (B).

Note:
Due to a decrease in atomic size across the period from left to right outermost electrons experience greater nuclear charge and become difficult to remove an outermost electron. While moving down the group due to an increase in atomic size less energy is required to remove the outermost electron. Hence metallic character decreases across a period and increases down the group.