why do you think you can find silver and gold on their own in rocks but calcium and magnesium are combined with other elements to make compounds such as calcium carbonate and magnesium sulfate?

Explanation:

Silver and Gold belong to a special group of metals known as the native metals. They are found naturally on their own and not in combined form in rocks.

These metals are found uncombined because they are unreactive. They prefer to alloy with themselves. Calcium and magnesium on the other hand are reactive metals. The unreactivity of these metals makes them uncombined in nature.

What record? the question is incomplete

Answer; carbon monoxide (co);