Step 1. Typical energy scale of atomic levels Atomic energy levels (like in the hydrogen atom) are of the order of electron volts (eV). E‌atomic ‌∼1eV Step 2. Typical energy scale of nuclear levels Nuclear energy level spacings are typically in the range of MeV (mega electron volts): E‌nuclear ‌∼1MeV=106eV Step 3. Ratio of orders ‌