Stable elements cannot be made unstable without external influence, as their nuclei are energetically favorable in their stable state. However, it is theoretically possible to induce radioactivity by exciting the nucleus to a state above its decay threshold, which can lead to decay processes. This can be achieved through methods such as applying electromagnetic radiation or bombarding the nucleus with particles. An example is lithium-6, which remains stable until promoted to an excited state, becoming unstable and capable of alpha emission. The concept of induced radioactivity was recognized with a Nobel Prize in 1935, paving the way for advancements in nuclear technology.