Why everything (except helium) does solidify at 0K?

Answer 1

Because there is no longer enough energy in the individual atoms to maintain the viscousity of liquids/gases. And helium turns into a superfine, monatomic powder. ^_^

Answer 2

To be honest, i don't think that reaching 0K is possible, even if it is possible, then heilum probably would solidify (provided that they're close enough together) as the particles would stop moving altogether.

Answer 3

Helium solidifies at a few millikelvin, so your question doesn't make sense.

Baloney he used it at a microkelvin, you can't get a dilution refrigerator below 1K. To go below this temp you have to use magnetic refrigeration or a laser trap. No way did he get bulk He to cool below 1K.

Answer 4

0 K is basically a theoretical endpoint, not something we can actually reach.

If helium acted differently from other elements, my best guess would be because it's the only inert gas that has two valence electrons instead of eight.

Answer 5

Because it does not readily form bonds.

In fact helium does form a solid, but only at high pressure (25 atmospheres) and OK.

It is most definitely still a liquid at a microkelvin because I have done experiments with it at this temperature.