Phosphorus is a nonmetal that exists in a variety of different forms (allotropes). The most common forms are white and red phosphorus. These different forms of this element all have very different properties. Phosphorus is highly reactive, which means that it is never found in its elemental form in nature. However, it is very common in a number of different minerals and makes up about 0.1% of all rocks. Phosphorus is a chemical element with the atomic number 15 and the chemical symbol P. All naturally occurring phosphorus on Earth is made up of a single stable isotope. However, many other isotopes of phosphorus have been identified.
How many isotopes does phosphorus have?
Phosphorus has only one stable isotope, which means that it is a monoisotopic element. The stable isotope is Phosphorus-31 (31P).
There are 22 unstable (radioactive or radioisotopes) isotopes of phosphorus that have also been identified. These range from 24P to 46P and most of these have half-lives of less than a second. The longest-lived radioisotopes of phosphorus are 33P, which has a half life of 25.34 days, and 32P, which has a half life of 14.263 days.
The shortest lived radioisotope of phosphorus is 25P, which has a half life of less than 30 nanoseconds. This may not be the most unstable isotope though as the half-life of 24P is not actually known!
Most of the unstable isotopes of phosphorus with a mass lower than 31P decay to silicon and those with a mass higher than 31P decay to sulfur.
Did you know?
The most stable radioactive isotopes of phosphorus are both used in scientific laboratories for various reasons. 32P is hazardous to human health because it is a beta-emitter and must be shielded to protect humans working with it.