What happens to electronegativity across a period?

Electronegativity increases across a period primarily because of the increase in nuclear charge. As you move from left to right on the periodic table, the number of protons in the nucleus increases, which enhances the positive charge acting on the electrons that are held more tightly. This stronger attraction between the positively charged nucleus and the negatively charged electrons means that atoms are generally better at attracting electrons from other atoms, leading to an increase in electronegativity.

As a result, elements that are found later in a period typically have a higher tendency to attract bonding electrons compared to those found earlier in the same period. This trend is why electronegativity values increase across a period.

Factors like atomic size and ionization energy do play roles in determining electronegativity but affect it in different ways. Atomic size, for instance, generally increases down a group which can lead to decreased electronegativity, but moving across a period, the atomic radius actually decreases, complementing the trend of increasing electronegativity. Similarly, while higher ionization energies might indicate an atom’s ability to hold onto its electrons more tightly, it does not directly dictate what happens to electronegativity across a period. The key factor in this case remains the increasing nuclear