Question

in nature Aluminium is found in combined state whereas silver is found in free state

Answer 1

The metal Aluminium is more reactive then silver hence aluminium is found in combined state with some another metals due to its high reactivity where as silver is less reactive or Noble metal it is found in free state.

Answer 2

gold silver and plantinum all occurs in free state .in nature because that is the nature of nature gold plantinum are not subject too much oxidation as they occur in nature