Metals rule the world

Metals are shiny, malleable, fusible hard materials readily conducting heat and electricity. The mobility of electrons within the bulk solid accounts for their peculiar properties useful for technological applications. Different metals also allow mixing to form alloys, possessing properties suited to applications.

- BY Pror. KIRTHI TENNAKONE

Matter we see on the earth is constituted of 93 chemical elements, of which 66 have metallic properties. Prehistoric man identified metals incidentally and exploited them for advantage using empirical techniques. Later, chemists studied metals for curiosity, and their findings paved the way for numerous applications that transformed the world.

Metals rule the world. They profoundly shaped human civilisa-tion, advancing technology and therefore social structure in distinctive leaps. For that reason, the historical periods after the Neolithic are often named after metals: copper, bronze and iron. Metals, subsequently introduced through the efforts of chemists and engineers, opened new eras of technology.

Today, we see things made of aluminum everywhere, but no one saw aluminum until 1825, when the metal was first extracted by the Danish physicist Christian Oersted. Four decades later, an electrolytic method was developed to obtain aluminum from the ore bauxite. Thereafter, the metal previously considered to be the most precious, owing to its resistance to extraction via conventional methods, reached the status of a versatile metal superior to iron and copper in many applications. Today, it would be hard for us to live without aluminum.

Indispensable aluminum artifacts are part of our routine.

Uranium, the heaviest metal on earth, progressed our understanding of matter and the cosmos, changed the political landscape and remains as an ample source of energy.

Now we are witnessing the dawn of another era defined by a series of metals known as rare earths. Crucial sectors of advanced technology indispensably rely on these metals. Rare earth metal processing continues to be a monopoly of China, producing nearly 90 percent of the global demand. Recently, other industrial nations have expressed concerns regarding secure supplies of rare earth metals, because of the possibility of trade embargoes and sensitive political issues.