Why does Beryllium have a larger first Ionization energy than boron?

Question

anonymous · Answer

Beryllium is a metal, and Boron is a non-metal. Metals tend to have low electronegativity, which means they hold loosely to their electrons, resulting in a high ionisation energy- they can lose electrons quickly. Boron is a non metal so it has a high electronegativity, and the positive nuclei has much strength is holding electrons tightly, which means it has a low ionisation energy, it is harder to lose electrons.

anonymous · Answer

This is also due to the masses of both elements, so they will have their positive nuclei will have different levels of attraction.