Answer and Explanation:
The elements can be ranked according to their ionization energy from highest to lowest as follows:
1. Bromine
2. Iodine
3. Antimony
4. Krypton
Ionization energy refers to the amount of energy required to remove an electron from an atom or ion in the gas phase. Generally, ionization energy increases as you move across a period from left to right on the periodic table. This is due to the increasing effective nuclear charge, which makes it more difficult to remove electrons.
Bromine has the highest ionization energy among the given elements. As you move from bromine to iodine, the ionization energy decreases, indicating that iodine is easier to remove an electron from compared to bromine. Similarly, the ionization energy decreases from iodine to antimony, and finally to krypton, with krypton having the lowest ionization energy among the given elements.
It's important to note that the exact values of ionization energy can vary depending on factors such as atomic structure and electron configuration, but the general trend of increasing ionization energy from bromine to krypton holds true.