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
The Elements of Style "a splendid trophy for all who are interested in reading and writing." American poet Dorothy Parker once proclaimedIf you have any young friends who aspire to become writers, the second-greatest favor you can do them is to present them with copies of "The Elements of Style". The first-greatest, of course, is to shoot them now, while they’re happy. Criticism of "Strunk & White" has largely focused on claims that it has a prescriptivist nature, or that it has become a general anachronism in the face of modern English usage. In criticizing "The Elements of Style", Geoffrey Pullum, professor of linguistics