Isotopes of helium a thousand times lower than helium-4 (2.17 K). This difference is explained by quantum statistics, since helium-3 atoms are fermions, while helium-4 atoms are bosons, which condense to a superfluid more easily. The most common isotope, , is produced on Earth by alpha decay of heavier radioactive elements; the alpha particles that emerge are fully ionized nuclei. is an unusually stable nucleus because its nucleons are arranged into complete shells. It was also formed in enormous quantities during Big Bang nucleosynthesis. Terrestrial helium consists almost exclusively (99.99986%) of this isotope. Its boiling point of 4.2 K is the lowest of
Boiling Point: Road to Hell Boiling Point: Road to Hell Boiling Point: Road to Hell ("Xenus: Точка кипения", "Xenus: Boiling Point") is a video game developed by the Ukrainian game studio Deep Shadows and published in 2005 by Atari. Boiling Point's gameplay is a combination of open world, FPS, and role-playing video game mechanics. Critical response upon its release was, with few exceptions, lukewarm. This was attributed to the many technical issues that plagued the game's release: bugs, glitches and choppy performance. Patches have been released that address many, but not all, of these deficiencies. Deep Shadows released a successor in 2009 called "", and