Look for an aluminum foil or use an aluminum foil for packaging in a cigarette box and fold it into a duck shape (note that the aluminum side is outward). Use a brush to rub the mercury nitrate solution, brush it around the aluminum duck, or bathe the aluminum duck in a solution of mercury nitrate, and then use the cotton wool or clean cloth to absorb the excess liquid from the duck. After a few minutes, you will be amazed to see that the duck has grown white fur! What's even more strange is that after the hair of the duck is wiped off with cotton, it will re-grow new hair.
  Why do aluminum ducks have long hair? What is the hair that grows? It turns out that aluminum is a more active metal that is easily oxidized by oxygen in the air to become alumina. The reason why ordinary aluminum products are protected from oxidation is that the surface of the aluminum product is protected by a dense alumina coat. After the surface of the aluminum foil is coated with a solution of mercury nitrate, the mercury nitrate passes through the protective layer and undergoes a displacement reaction with aluminum to form a liquid metal, mercury. Mercury can be combined with aluminum to form an alloy. Commonly known as "aluminum amalgam", aluminum on the surface of aluminum amalgam does not have the protection of an aluminum oxide protective film, and is quickly oxidized by oxygen in the air to become white solid alumina. When the aluminum on the surface of the aluminum amalgam is reduced by oxidation, the aluminum on the aluminum foil dissolves continuously into the aluminum amalgam and continues to oxidize on the surface to form white alumina. Finally, the duck made of aluminum foil is covered with white hair.
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