How does the electronegativity of p-block elements change across a period?

In general, the electronegativity of p-block elements tends to increase across a period from left to right. This trend is due to the increasing nuclear charge across the period, which leads to a stronger attraction for electrons in the outermost p orbitals.

As you move from left to right across a period, the number of protons in the nucleus increases, leading to a stronger positive charge in the nucleus. This increased positive charge exerts a stronger pull on the valence electrons in the p orbitals, resulting in higher electronegativity values.

However, there can be exceptions to this trend due to factors such as electron configuration and atomic structure. For example, elements like nitrogen and oxygen have higher electronegativities compared to the elements immediately following them in the same period, despite having fewer protons. This is because of their small atomic sizes and the presence of half-filled or completely filled p orbitals, which contribute to their strong electronegativities.