Would an atom with high electronegativity be more likely to react with an atom with high ionization energy or

low ionization? WHY?

It would be more likely to react with an atom with low ionization energy. Electronegativity refers to an atoms ability to attract electrons to it. If it has a high electronegativity, it has an easier time attracting electrons. This is important when it comes to forming bonds in which electrons are being shared (like in covalent bonds).

Ionization energy refers to how much energy is required to remove an electron from an atom. A high ionization energy means that it is much harder to remove an electron, and therefore it would be more difficult to share electrons and form a bond. The reason it is harder to remove an electron is because the electrons are being pulled more closely towards the nucleus. This is related to the size of the atomic radius because the smaller the radius, the closer the valence electrons are to the nucleus. If you know the periodic table trends, they are relatively easy to predict. Anyway, if an atom has a low ionization energy, the electrons are a little less close to the nucleus because the attraction is weaker, so it is easier to remove/share them.

This is ideal because the atom with the high electronegativity should have no problem attracting the electrons from the atom with low ionization energy and forming a bond during a reaction.

Does that make sense?