Answer:
The correct option is;
Element 2
Step-by-step explanation:
The ionization energy is the energy required to eject an electron from a gaseous ion or atom
The ionization energy increases across the period and increases up the group
The elements with the highest ionization energy are those that have the complete octet structure in their outermost shell, which are the noble gases
Therefore, given that element 2, which has the complete octet structure in the outermost shell, then it is an element of the noble gases which have the highest ionization energy in a period, and therefore has the highest ionization energy.
On the periodic table, the element with 10 electrons is Neon, with ionization energy of 2080.68 kJ/mol which is the second highest after helium, that has only 2 electrons.