In the experiment, scientists turned purified water into metal for a few fleeting seconds, allowing the liquid to conduct electricity.
Unfiltered water can already conduct electricity – that is, negatively charged electrons can easily pass between its molecules – because unfiltered water contains salts, according to a statement about the new study. However, purified water contains only water molecules, whose extreme electrons remain bound to said atoms, and therefore they cannot pass freely through the water.
Theoretically, if enough pressure is applied to pure water, the water molecules are squeezed together and their valence shells-the outer rings of electrons surrounding each atom-overlap. This allows the electrons to move freely between the molecules and technically turns water into a metal.
The problem is that to compress water to a metallic state requires a pressure of 15 million atmospheres (about 220 million pounds per square inch), study author Pavel Jungwirth, a chemical physicist at the Czech Academy of Sciences in Prague, told Nature News & Comment. For this reason, geophysicists suspect that such water transformed into metal may exist in the cores of huge planets such as Jupiter, Neptune and Uranus, Nature News reported.
But Jungwirth and his colleagues wondered if water could be turned into metal in other ways without creating the ridiculous pressures seen in Jupiter’s core. They decided to use alkali metals, which include elements such as sodium and potassium and have only one electron in their valence shells. Alkali metals tend to “give up” this electron to other atoms when forming chemical bonds, because the “loss” of the single electron makes the alkali metal more stable.
Alkali metals can explode upon contact with water, and Jungwirth and his colleagues have indeed studied these dramatic reactions in the past, according to the journal Cosmos. But they suggested that if they could somehow avoid exploding, they could borrow electrons from the alkali metals and use them to turn water into metal.
In their new experiment, described in a report published Wednesday (July 28) in the journal Nature, the team did just that. In the experiment, they placed a syringe filled with sodium and potassium in a vacuum chamber, squeezed out small drops of the metals that are liquid at room temperature, and then exposed the metal drops to tiny amounts of water vapor. The water formed a 0.000003-inch (0.1 micrometer) film on the surface of the metal droplets, and immediately electrons from the metals began rushing into the water.
For the experiment to succeed, the electrons had to move faster than an explosive reaction could, Jungwirth told Nature News. And once the electrons rushed from the alkali metals into the water, the unbelievable happened: For a few brief moments, the water turned a brilliant, golden yellow color. Using spectroscopy, the team was able to show that the bright yellow water was actually metallic.
“Our study not only shows that metallic water can indeed be produced on Earth, but also characterizes the spectroscopic properties associated with its beautiful golden metallic luster,” study author Robert Seidel, head of the young research team at Humboldt University Berlin, said in a statement. “The phase transition into metallic water can be seen with the naked eye,” he added.
“It was amazing how [when] you discover a new element,” Jungwirth told Nature News & Comment.