1. Helium has a near identical melting and boiling point, and the lowest of all the elements. It’s melting point is so close to absolute zero that nothing else is cold enough to freeze it, so scientists have to use specially built pressure chambers to solidify it.
2. It is stable with just two valence electrons as opposed to all other noble gases requiring eight electrons.
3. Near absolute zero, helium becomes a superfluid where it gains zero viscosity.
4. It has the highest thermal conductivity of any element which makes it an excellent coolant.
5. It is naturally non-toxic and the most chemically inert of all elements.
6. One of it’s only known ions, helium hydride, is the strongest acid ever observed.
What gives? Why is it such a wonder substance and why does it display such unique traits compared to other elements?
In: Chemistry
It is special because it is the first noble gas as well as only the second element out of all. You can easily make such a list for hydrogen as well, it as the first element has a lot of properties not found later on.
> Helium has a near identical melting and boiling point
It doesn’t freeze at standard pressure, so that is a weird statement. Also iodine has a very narrow liquid range as well, and this is not the only example.
> It’s melting point is so close to absolute zero that nothing else is cold enough to freeze it
There simply is no melting point. You need pressure. The ultimate reason is that “0 K” cannot be reached and everything always has some “basic energy”, the _zero-point energy_. For a very simplified ELI5 explanation, you can understand it as a certain temperature it cannot get below.
> It is stable with just two valence electrons as opposed to all other noble gases requiring eight electrons.
Just an effect of the first shell only admitting 2 electrons. The later ones simply hide it below other orbitals.
> Near absolute zero, helium becomes a superfluid where it gains zero viscosity.
True, but this is not unique to helium. Other substances however require different pressures. You by the way need He-4, He-3 won’t work for superfluidity as you need _bosons_.
> It has the highest thermal conductivity of any element which makes it an excellent coolant.
Under what situations? At normal temperature diamond should beat it hands-down. When superfluid then yes, but that is cheating; other superfluids also would have really high heat conductivity.
> It is naturally non-toxic
So are iron, nitrogen, and many more.
> the most chemically inert of all elements.
True. Due to its nature as smallest noble gas.
> One of it’s only known ions, helium hydride, is the strongest acid ever observed.
Helium as the leat reactive element wants to get rid of whatever you “stick” to it. In this case hydrogen, and wanting to donate hydrogen is literally what defined pH.
Latest Answers