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
Death by boiling Death by boiling Death by boiling is a method of execution in which a person is killed by being immersed in a boiling liquid. While not as common as other methods of execution, boiling to death has been used in many parts of Europe and Asia. Executions of this type were often carried out using a large vessel such as a cauldron or a sealed kettle that was filled with a liquid such as water, oil, tar, or tallow, and a hook and pulley system. In England, the 9th statute passed in 1531 (the 22nd year of the reign of