Modern Alchemy Turns Water into A Golden Metal

The obsession with gold lead alchemists in the medieval ages to desperately try every trick in the book to convert metals like iron and copper to gold. Probably not wanting their efforts to go waste, a team of modern (al)chemists have innovated a method to transform water into a shiny, golden, metallic material. Yes, it is true – water can indeed demonstrate metallic behaviour, albeit only for a few seconds!

Though water present naturally on earth is able to conduct electricity, it is only because of the impurities contained in it. Pure water is a very good insulator, i.e., it does not allow electron flow. However, in a set of cleverly-designed experiments, a team of scientists lead by Pavel Jungwirth from Czech Republic were able to demonstrate electrically conductive behaviour of water, and even transformed it into a shiny, metallic substance.

Theoretically, almost any material can become conductive under enormous pressure. In such conditions, the atoms are squeezed together so strongly that they begin sharing electrons and conducting electricity. For water, the pressure required to make it conducting is millions of times the Earth’s atmospheric pressure at sea level. It is definitely impractical to create such conditions in the lab. But Jungwirth and his team devised an ingenious method to turn water into metal.

They achieved this feat by bringing water into contact with alkali metals. Alkali metals are elements present in Group 1 of the periodic table, and are so named because they react with water to form alkalis (strong bases which can neutralize acid). The defining feature of alkali metals is that they all have one electron in their outermost orbit, which they are very eager to get rid of. Since they donate their outer electron so readily, they could be used to induce electron-sharing properties. However, alkali metals react violently with water, and sometimes even cause explosions. The research group found a unique way to address this problem. Instead of adding the metal to water, they allowed water to deposit on the surface of the metal. The experiments consisted of taking a solution of potassium and sodium into a syringe and placing it in vacuum (space devoid of matter). Small droplets of the metal were allowed to form, which were then very carefully exposed to water vapour. The water vapour condensed on the surface of the metal droplets and voila! A golden, metallic layer of water was formed as electrons from the metal diffused into water. To avoid an explosion, the researchers carefully optimized the time of contact which was just enough for the water to accept the electrons without further reacting with it. The result was marvelous – not only did water become conductive just like a metal, but it also acquired a golden hue. Moreover, the transition of water into the golden state could be seen with the naked eye. Prof. Jungwirth said that this was the highlight of his career, and though all this may sound like fantasy, it is a reminder that science is a lot of fun.

What significance does this experiment have? First, it can help understand the phase transitions of water upon reaction with different substances. In addition, it can also help us understand high-pressure conditions in planets like Uranus and Neptune, where liquid metallic hydrogen and ice are thought to be present. The prospect of being able to replicate conditions observed on other planets is pretty exciting, and may uncover several secrets. This exciting study was recently published in the journal Nature.