Identifying the Element with the Highest Ionization Energy

Consider the elements from the periodic table, specifically focusing on their atomic structure and the trends within the periodic table. The atomic number of an element is defined as the number of protons in its nucleus, which directly correlates to its position in the periodic table. As you move from left to right across a period, one observes an increase in atomic number, while certain periodic trends such as ionization energy and electronegativity typically increase across a period. Among the elements listed below, which element possesses the highest ionization energy?