Answer:
1 and 4.
Step-by-step explanation:
Hello,
Since nonmetals are located to the right of the periodic table, they have both relatively high ionization energies and high electron affinities, therefore they tend easily gain electrons and toughly lose them. In addition, they have more valence electrons and are very close to accomplish the octate.
In this case, the largest two ionization energies belong to the 1 and 4 elements.
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