Question

Given that the total number of atoms on our planet remains fairly constant, how is it ever possible to deplete a natural resource such as a metal?

Answer 1

Natural Resources are not depleted on the atom level, but on the molecular level. Everything eventually transforms into something else, be either throughtime or human action.

For example, Petroleum can be be transformed into other materials such as gasoline or plastic and thus be depleted in its natural state.

Atoms can be combined with other molecules in order to form other materials useful for mankind.

However, some materials after being used are not recycled (such as plastic bags) or are unable to be recycled (nuclear waste for example) . Therefore beingdepleted.

But I believe the key answer is that natural resources can be transformed and thus be depleted on its original state.Thus number of Atoms is constant, butnumber of atoms in its pure form is not.

Answer 2

Large concentrations of these metals are becoming much harder to find over time. Currently mined or known resources of these metals are being depleted andnot recycled.