Explanation:
It is more difficult to remove electrons from the second shell or energy level because of the imbalance between the positive nuclear charge and the remaining electrons.
- The amount of energy required to remove electrons in ground state of an atom is the ionization energy.
- The first ionization energy is the energy needed to remove the most loosely bound electron of an atom in the gas phase in ground state.
- The second energy has a greater nuclear pull as it is closer to the nucleus.
- Both potassium and silicon have the same number of energy levels.