[conservative_crusader]

Because, all radioactive elements have displayed a tendency to decay into lead. We also know, that all elements are slightly radioactive, although the amount of radioactivity is very slight compared to deadly amounts. So, we can conclude that all elements will eventually decay into lead.

[curiosity]

Because, all radioactive elements have displayed a tendency to decay into lead. We also know, that all elements are slightly radioactive, although the amount of radioactivity is very slight compared to deadly amounts. So, we can conclude that all elements will eventually decay into lead.

This is the first I've ever heard this. I took nuclear chemistry a long time ago, and I don't remember this being discussed. Maybe someone with some expertise on the topic can clarify it.

[curiosity]

Come to think of it, what you propose is wrong. When a radioactive element decays, it decays into something lighter. Therefore, even if elements lighter than lead are decaying, they cannot possibly decay into lead.

Ergo, even if the universe were infinitely old, it would not be 100% lead.