Question

In general, electronegativity ______ as atomic size increases because a shared electron pair is closer to the nucleus of a smaller atom, which therefore attracts these electrons ______ strongly. Thus, electronegativity tends to ______ from left to right across a period of the periodic table and tends to ______ down a group.

Answer 1

Electronegativity decreases as atomic size increases and it increases from left to right across a period of the periodic table while decreasing down a group, due to changes in atomic size and nuclear charge.

Step-by-step explanation:

In general, electronegativity decreases as atomic size increases because a shared electron pair is closer to the nucleus of a smaller atom, which therefore attracts these electrons more strongly. Thus, electronegativity tends to increase from left to right across a period of the periodic table and tends to decrease down a group.

The periodic trend in electronegativity shows that as we move from left to right across a period, the electronegativity increases due to the decrease in atomic size and increase in nuclear charge, making the nucleus more effective at pulling the bonding electron pair to itself.

Conversely, as the atomic size increases down a group, the distance between the nucleus and the bonding electrons becomes greater, leading to a decrease in electronegativity. This explains why halogens, which are found on the right side of the periodic table, have high electronegativities compared to alkali metals found on the left.