Explanation: Ionization energy is defined as the amount of energy required to remove an electron from the outermost shell of an isolated gaseous atom.
General equation of ionization energy is given by:
If the outermost electron is loosely bound to the nucleus which means that the electron can be easily removed form an atom, it will require less amount of ionization energy.
And if the outermost electron is tightly bound to the nucleus which means that the electron cannot be removed easily from an atom. And hence, it will require more ionization energy.
Even though there is no answer choices. I know this has something to do with Charles Darwin and his experiments when he went to the Galápagos islands when he studied the finches