Question

Shortly write 5 characteristics of a group in the periodic table

Answer 1

Answer:

Characteristics of a Group:

1:Valency:

In a group, all the elements have the same valency. For example, the group I elements: Li, Na, K, etc., all have a valency of +1. Elements of group 17: CI, Br, I, etc., all have a valency of -1.

2:Size of atoms:

Atomic radii or the size of atoms of the element increase on going down a group this is due to the addition of new electronic shells.

3:Metallic character:

On descending a group the metallic character increases. For example, groups 14 and 15 begin with carbon and nitrogen which are non-metals.

These groups end with lead and bismuth respectively which are metals. The oxides of the elements also become increasingly basic.

4:Melting and boiling points:

The melting and boiling points of metals decrease in going down in a group, for example, the alkali metals of group 1 decrease gradually on going down the group. Li (m. pt. 180.5°C, b. pt. 1347°C), K (m. pt. 63.4°C, b. pt. 774°C).

The melting points and boiling points of non-metals increase on going down in a group. For example, the melting points of the group 17 increase gradually on going down in the group. F (m. pt. -219.6°C), I2 (m. pt. 113.6°C)

5:Ionization energy:

Ionization energy decreases on moving down a group with the increase in atomic number. This is because the size of the atom increases and the valency electrons are farther removed from the attractive effect of the nucleus.

6:Chemical reactivity:

The chemical reactivity of metals increases in going down a group. For example, in group 1 of alkali metals, the chemical reactivity increases from lithium to francium.

On the other hand, the chemical reactivity of non-metals decreases on going down in a group. For example, in group 17 of halogen elements (non-metals), fluorine is most reactive and iodine is the least reactive.

HOPE IT HELPS