P32 has 15 neutrons and 17 protons.
Number of neutrons in Phosphorus? P Phosphorus is a chemical element with the symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but because it is highly reactive, phosphorus is never found as a free element on Earth. Instead, it has a concentration of about one gram per kilogram (about 0.2% by weight). In minerals, phosphorus generally occurs as phosphate.
White phosphorus is the most common allotrope of phosphorus. It is used extensively as an incendiary agent and smoke screen precursor. Still, due to its high reactivity – it will burst into flames spontaneously in air at about 30 °C (86 °F) – white phosphorus must be stored underwater to prevent exposure to the air. Red phosphorus may be formed by heating white phosphorus to 400 °C (752 °F) without oxygen or by exposing it to sunlight. It is used as a fire retardant and in some matches and fireworks. Black phosphorus can be formed by heating white phosphorus under high pressure (around 10GPa) or chemical vapor deposition. It is a semimetal with properties similar to those of graphite.
Phosphorus has some unusual properties compared to other elements; for example, it expands when it freezes, unlike all other solids (with the exception of bismuth, germanium, antimony, and gallium). Also, at temperatures above about 150 K (−123 °C; −189 °F), phosphorus becomes progressively more conductive, eventually becoming a superconductor at temperatures above about 200 K (−73 °C; −100 °F).
Phosphorus is essential for life. It is a component of DNA and RNA, and it plays an important role in the metabolism of cells. Phosphates are also used in many industrial processes, such as the production of fertilizers, detergents, and phosphoric acid.
The most common naturally occurring isotope of phosphorus is 31P, with a concentration of about 100%, followed by 30P (about 0.1%). Phosphorus has 25 known isotopes, all of which are radioactive. The longest-lived radioisotopes are 32P (14.28 years) and 33P (25.3 days).
All other isotopes have less than two weeks, and most have half-lives of only a few seconds. For example, the shortest-lived known isotope is 28P, with a half-life of 20 milliseconds.
Phosphorus is produced commercially by reducing phosphate rock with elemental phosphorus or aluminum phosphide. Large quantities of white phosphorus are also produced as a byproduct of calcium carbide (CaC2) production from calcium oxide (CaO) and coke. Smaller quantities are produced in the laboratory by reducing sodium hypophosphite (NaH2PO2).