Is it easier to ionize high energy or low energy electrons?

Ionization refers to the process of removing an electron from an atom or molecule, and the energy required to do this depends greatly on the energy of the electron being removed. High energy electrons are typically already in an excited state, which means they are further away from the nucleus and less tightly bound to the atom. This makes it easier to remove them because the attractive force that the nucleus exerts on these electrons is weaker compared to those that are in lower energy states.

In contrast, low energy electrons are closer to the nucleus and are held more tightly due to stronger electrostatic attractions. As a result, more energy is required to ionize these electrons because one needs to overcome the stronger forces holding them in place.

Thus, high energy electrons are easier to ionize than low energy electrons, making this choice the correct answer.