Mention the part of group where the elements show:
(i) Highest metallic character (ii) Big atomic size
Answers
The part of a group where the elements show the
(i) Highest metallic character and (ii) big atomic size is the bottommost part of the group.
i) • The highest metallic character is observed in the bottommost position in a group.
• The metallic character of an element depends upon its tendency to lose electrons. The more the ability to lose electrons, the greater is the metallic character.
• On moving down a group, the atomic size increases due to the addition of shells with each successive period.
• This increases the distance between the nucleus and the valence electrons, and consequently, the nuclear pull decreases.
• Due to the decreasing nuclear pull, the elctrons are readily lost by the atoms, which increases the metallic character of the elements.
• Therefore, the metallic character increases on moving down in a group, and is the highest in the lowest position of the group.
ii) The biggest atomic size is also found in the bottommost position in a group.
• As we move down in a group, the period number increases.
• With each successive period, an extra shell gets added to an atom, in which the elctrons are filled.
• This causes a decrease in the nuclear pull on valence electrons due to an increase in the distance between them.
• Therefore, the atomic size increases as we move from top to bottom down a group, and is the biggest in the bottommost position.
Metallic character and atomic size
Explanation:
Within a group, the metallic character increases as we move from top to bottom of the periodic table. An element that has the tendency to lose electrons is said to be metallic.
Within a group, the atomic size increases as we move from top to bottom of the periodic table. The atomic size increases due to the increase in atomic number, hence resulting in additional shells. As the distance between the nucleus and the outermost electrons increases, the atom tends to lose the valence electrons easily as the nuclear pull is reduced. This increases the metallic character of these elements. So the highest metallic character is exhibited by the lowest position of a group in the periodic table.
So, both the metallic characteristic and the atomic size increases as we move from top to bottom of a group.