Question

Name a metal found in the earth's crust:
(i) in free state and
(ii) in the form of its compound.
State where each of these metals are placed in the reactivity series of metals

Hint:

Metals found in free state are usually those that are least reactive, like gold, whereas metals in compound forms like aluminium are more reactive.

Answer 1

(i) In Free State: Gold (Au) is found in free state in the Earth's crust. It is one of the least reactive metals and is placed low in the reactivity series.
(ii) In Compound Form: Aluminium (Al) is found in the form of its compound, such as in bauxite. It is a highly reactive metal and is placed high in the reactivity series.
Thus, gold is placed low in the reactivity series, while aluminium is placed high in the reactivity series.