Question

State the trends in the variation of electronegativity in groups and periods.

Answer 1

1. Variation of electronegativity in a group: The electronegativity decreases down a group. As we move down a group, the atomic radius increases, and the nuclear attractive force on the valence electron decreases. Hence electronegativity decreases in a group.

Variation of electronegativity along with I group

2. Variation of electron negativity in a period: The electronegativity increases across a period from left to right. Since the atomic radius decreases in a period, the attraction between the valence electron and the nucleus increases. Hence the tendency to attract shared pair of electrons increases. Therefore, electronegativity increases in a period.

Variation of electronegativity along with II group