Using the activity series, explain the reason that most metals cannot exist in nature as elements but are found as compounds instead. Use specific examples to explain your answer. (Hint: Consider the reactivity of metals with water)
Those metals at the top end of the activity series are so reactive they form oxides, hydroxides, carbonates, etc.
Na is one example. You can find NaCl, Na2CO3, NaI, and other compounds but not free Na atoms.