What is a primary characteristic of elements in the upper right of the periodic table?

Elements in the upper right of the periodic table, which includes nonmetals and especially noble gases, are characterized by having higher ionization energy. Ionization energy is the amount of energy required to remove an electron from a gaseous atom or ion. As you move from left to right across a period in the periodic table, the ionization energy generally increases due to the increase in nuclear charge with the addition of protons. This increased nuclear attraction makes it more difficult to remove an electron from the outer shell, thus requiring more energy.

Higher ionization energies are typically associated with elements that have nearly full valence electron shells, making them more stable. This stability translates into a higher energy requirement to remove electrons compared to elements with lower ionization energies, which are usually located farther to the left in the periodic table.

The other choices can be addressed in context. While elements in the upper right may possess varying electronegativities, they generally exhibit higher electronegativity rather than lower. Moreover, the tendency to form cations is more characteristic of metals, which are found on the left side of the table rather than the upper right. Additionally, atomic radius tends to decrease from left to right across a period, which is opposite to what the last