> Intuition suggests that metals are dense, and while that bears true for some (think gold or lead), it fails to hold up for others. For example, lithium—commonly used in batteries—floats on water. Some metals are hard, such as titanium, yet others yield easily to pressure, including indium and aluminum. How about melting temperature? Platinum melts at more than 1,700 degrees Celsius (3,200 F), but mercury is a liquid well below zero.<p>What makes a metal a metal has been known for many decades. It's the tendency to donate electrons. The article makes it sound like this is some kind of mystery that textbooks don't yet explain. Not so by a long shot.<p>> In these solutions, electrons from the alkali metal initially become trapped in the gaps between ammonia molecules. This creates what scientists call 'solvated electrons,' which are highly reactive but stabilized in the ammonia. These solutions have a characteristic blue color. But given enough solvated electrons, the whole liquid turns bronze and, in essence, becomes a metal while remaining liquid.<p>This is a Birch Reduction, which was first reported in 1944 based on earlier research:<p><a href="https://en.wikipedia.org/wiki/Birch_reduction#History" rel="nofollow">https://en.wikipedia.org/wiki/Birch_reduction#History</a><p>From the article:<p>> The results showed that, at low concentrations, solvated electrons were more easily dislodged from the solution by the interaction with the X-rays, giving a simple energy pattern. At higher concentrations, though, the energy pattern suddenly developed a sharp band edge, indicating the solution was behaving as a metal would.<p>Maybe there's something interesting here, but you sure can't tell from the article.<p>There's no link to primary research anywhere that I can see. There's really no excuse for this.<p>Edit: found the paper at the bottom:<p><a href="https://science.sciencemag.org/content/368/6495/1086" rel="nofollow">https://science.sciencemag.org/content/368/6495/1086</a><p>Behind a paywall...
> The academics McMullen contacted at other U.S. research universities told him they had funding for their own research, but not for his. But Bradforth had a different response.<p>> "He said, 'I don't have funding for your idea but if you come over here we can write a funding proposal together,'" said McMullen, who at the time was finishing up his undergraduate studies...<p>> Bradforth not only helped McMullen secure funding, prioritizing it for National Science Foundation support over continuing other projects, but he also cobbled together an international team of scientists and arranged his sabbatical to oversee and participate in the main experiments. He also became McMullen's Ph.D. adviser.<p>Man you gotta love such an awesome prof
Some more detail from Derek Lowe at In The Pipeline:<p><a href="https://blogs.sciencemag.org/pipeline/archives/2020/06/24/ammonia-electrons-and-metals" rel="nofollow">https://blogs.sciencemag.org/pipeline/archives/2020/06/24/am...</a>
Reminds me of Dr. Banting and the isolation/discovery of insulin, ultimately leading to a nobel prize.<p>> Banting was no expert in the field of carbohydrate metabolism, so when he requested laboratory space and facilities from Professor John James Rickard Macleod, Head of Physiology at the University of Toronto, the esteemed physiologist was at first reluctant.<p>> However, Banting’s persistence and the possibility of more reliable results persuaded MacLeod to donate laboratory space. While tying up the pancreas to make it break down was not a new investigative tool, the idea of isolating islets due to their slower degeneration was of keen interest to Macleod.<p><a href="https://www.medicalnewstoday.com/articles/323774#development" rel="nofollow">https://www.medicalnewstoday.com/articles/323774#development</a>
Philip E. Mason also known as Thunderf00t on youtube is one of the authors. Here is a video explaining the experiment:
<a href="https://www.youtube.com/watch?v=DXpLAB5219A" rel="nofollow">https://www.youtube.com/watch?v=DXpLAB5219A</a>
Seems like it's related to a breakthrough for X-ray Photoelectron Spectroscopy that was originally thought to not be possible for liquids because it depends on having a vacuum, and the liquid would just evaporate. The solution was to use a microjet to spray a thin line of liquid, within the vacuum and cross that with the x-ray beam.
>"Seeking to further understand the intrinsic properties of metals, Bradforth, McMullen and their colleagues used a trick first noted by chemist Sir Humphry Davy in 1809. In essence, they made a metal from scratch.<p>The scientists cooled ammonia—normally a gas at room temperature—to minus 33 C to liquify it and then added, in separate experiments, the alkali metals lithium, sodium and potassium.<p>In these solutions, electrons from the alkali metal initially become trapped in the gaps between ammonia molecules. This creates what scientists call 'solvated electrons,' which are highly reactive but stabilized in the ammonia. These solutions have a characteristic blue color. But given enough solvated electrons, the whole liquid turns bronze and, in essence, becomes a metal while remaining liquid."