磷 (P)

發現史

發現: 1669 · Hennig Brand

Phosphorus was the first element to be "discovered", in the sense that it was not known since ancient times. The discovery is credited to the Hamburg alchemist Hennig Brand in 1669, who was attempting to create the fabled philosopher's stone. To this end, he experimented with urine, which contains considerable quantities of dissolved phosphates from normal metabolism. By letting the urine rot (a step later discovered to be unnecessary), boiling it down to a paste, then distilling it at a high temperature and leading the resulting vapours through water, he obtained a white, waxy substance that glowed in the dark and burned brilliantly. He named it in Latin: phosphorus mirabilis, lit. 'miraculous bearer of light'. The word phosphorus (Ancient Greek: Φωσφόρος, romanized: Phōsphoros, lit. 'light-bearer') is a reference to Phosphorus, god of the morning star in Greek mythology, known also as

用途與應用

Phosphorus has a concentration in the Earth's crust of about one gram per kilogram (for comparison, copper is found at about 0.06 grams per kilogram). It is not found free in nature, but is widely distributed in many minerals, usually as phosphates. Inorganic phosphate rock, which is partially made of apatite, is today the chief commercial source of this element. In 2013, astronomers detected phosphorus in Cassiopeia A, which confirmed that this element is produced in supernovae as a byproduct of supernova nucleosynthesis. The phosphorus-to-iron ratio in material from the supernova remnant could be up to 100 times higher than in the Milky Way in general. In 2020, astronomers analysed ALMA and ROSINA data from the massive star-forming region AFGL 5142, to detect phosphorus-bearing molecules and how they could have been carried in comets to the early Earth.

同位素

There are 22 known isotopes of phosphorus, ranging from 26P to 47P. Only 31P is stable and, therefore, has 100% abundance. The nuclear spin of 1/2 and high abundance of 31P make phosphorus-31 nuclear magnetic resonance spectroscopy a very useful analytical tool in studies of phosphorus-containing samples. Two radioactive isotopes of phosphorus have half-lives suitable for biological scientific experiments, and are used as radioactive tracers in biochemical laboratories. These are: