Question

this three dimensional version of the periodic table shows ionization energy trends. ionization energy is the energy required to remove a valence electron from a neutral, gaseous atom. ionization energy trends across periods are generally more consistent than electron affinity trends, although both are useful. use what you observe about ionization energy to explain why the halogens do not form positive ions.

Explanation:

Halogens have high ionization energies. This means a large amount of energy is needed to remove a valence - electron. As a result, it is difficult for halogens to lose electrons and form positive ions.

Answer:

Halogens have high ionization energies, making it difficult to remove a valence - electron and thus they do not form positive ions easily.