Question

Complete the following suitably:

In any vertical column of elements in a subgroup of the Periodic Table, as you go from top to bottom.

The electronegativity _________.

Answer 1

1. Electronegativity is a property of an atom in a molecule by virtue of which it has the tendency to attract the shared electron pair towards itself.
2. As one moves from top to bottom in a Group (column), the atomic number of elements increases, and the electrons are added to the new shells. Due to this, the valence electrons (electrons of the outermost shell) are placed far apart from the atomic nucleus. As a result, the bonded atom can not attract the electrons towards itself easily and strongly. Therefore, electronegativity decreases while one moves from top to bottom in a group/column.
3. Example, Fluorine (F) and Chlorine (Cl) both belong to the same group (Group 17) but Fluorine lies above Chlorine in the group. Therefore, Fluorine is more electronegative than Chlorine.
4. Hence, the electronegativity decreases down the Group.