The "Unfriendly" elements

There are elements call "Noble" - the name is historical. They are in group 8, that is, they already have enough electrons to cope with.

They can't take any more.

So they do not combine chemically with anything. They are known by the names Helium, Neon, Argon, Xenon, Krypton( beware superman) Xenon and the radioactive Radon.

Only Xenon is known to be remotely friendly. Due to the structure of the electrons, it can sometimes form compounds. But the rest remain safely uncooperative.

The most interesting is Helium. This element was first identified in the sun, from the light it gives out when heated, and then on earth. Because it is so unfriendly, it replaced Hydrogen as the gas used to fill airships, after the R101 etc.

But the real interesting stuff comes when you cool Helium down, because try as you may you cannot freeze it. It is a physical impossibility. Water you get as steam, water(of course), and ice, as the temperature goes down. You can solidify any element you like as long as you cool it enough.

But Helium point blank refuses to go into a solid. Why?

We don't actually know why Helium, but we do know what it does....

It pours itself out of its own container, it is has zero viscosity ( easier to move through than empty space), has zero resistance to electricity.

We have explanations for this behavior, but we still have little idea as to WHY it is Helium only that it was possible theoretically before.