Explanation:

 Learning: It is a very strong acid. It is made by mixing one part nitric acid and three parts hydrochloric acid.
• The acid was named by alchemists because it can dissolve the noble metals gold and platinum. Tantalum, iridium and a few other metals are not dissolved by it.
• It is also used to clean certain lab machines from tiny metal particles. It is particularly used in the purification and extraction of gold and platinum.
• It has an interesting history to it.
• When Germany invaded Denmark in World War II, the Hungarian chemist George de Hevesy took the Nobel Prize medals of Max von Laue and James Franck and dissolved them in Aqua regia so that Germans cannot take these medals.
• Later he submitted the dissolved Gold to the Royal Swedish Academy which again made medals for the Nobel laureates fromvthe gold.