Is there an element with high ionization energy and high electron affinity?
ionization energy is the energy required to remove an electron from a gaseous atom or ion. electron affinity is energy to attract an electron to form a negatively-charged ion. electronegativity is the ability of an atom to attract electrons in a covalent bond. Helium would have a very high ionization energy and an electron affinity of less than zero. Basically, all noble gases would have electron affinities less than zero because they have complete outer shells. Based on the octet rule the noble gases have 8 valence electrons, thus its already complete. It would take more energy to detach an electron from noble gases because they won’t give away something that makes them complete. And they have low electron affinities because they won’t or would less likely attract another electron since it is already too crowded.