Scientists are supposed to be sceptical of others claims – you will encounter this in NOS (NOS 1.7 ‘Scientists must adopt a sceptical attitude to claims’). Why do I quote this? Well, you may have recently read or seen in the news that a new form (state) of Hydrogen has been produced.
Hydrogen has been subjected to incredibly high pressure (495GPa or 495,000,000,000Pa – that’s 495 billion Pa). By contrast, standard atmospheric pressure is around 100,000Pa so this value is getting on for 5,000,000 or 5 million times greater!
This is a huge value, the pressure at the centre of the Earth’s core is only believed to be 360GPa so this information, I hope, helps put the idea pressure into perspective. It is believed that metallic hydrogen exists at the core of Jupiter, a planet large enough to have this sort of pressure at its core
By NASA/R.J. Hall – The background image is from NASA PIA02873. The overlaid cut-away illustration is by the contributor., Public Domain, https://commons.wikimedia.org/w/index.php?curid=1743608
And how was it achieved? Two industrial diamonds were squeezed together (they did also need to be subjected to other processes to stop them cracking).
At this high pressure, scientists have claimed that a previously predicted form of Hydrogen has been achieved. The atoms are forced close enough together so that the electrons delocalise and form a metallic structure (a sea of delocalised electrons surrounds the positive nuclei of hydrogen ions).
This is where I begin to get sceptical. I know that hydrogen is found as H2, so will this structure comprise of H2 molecules with delocalised electrons or is it H atoms that have some how been dissociated from molecules into atoms.
I want to be clear here, being sceptical is OK. It may seem negative but everything I have read on this (in newspapers and the internet) seems to skirt around this. Give me the answer (evidence) for what is happening and I’ll go along with it.
And this is the whole point of scepticism. The NOS of science statement 1.7 goes on (I quote) ‘This does not mean that they disbelieve everything, but rather that they suspend judgment until they have a good reason to believe a claim to be true or false. Such reasons are based on evidence and argument’.
As I said, give me the evidence and I’ll believe!
It has also been claimed that metallic hydrogen could be used as a super conductor at room temperature. This also makes me sceptical. When that incredible pressure is released, won’t the electrons return to the atoms, the atoms pair up and the structure flies apart? Or is there something I am missing. Again, give me the evidence and I will believe.
What do you think? Do you have the missing information I am looking for? Or do you have any other examples of scepticism in chemistry (science). As ever, it would be great to read your thoughts below.