31P

31P refers to the most stable and abundant isotope of the element phosphorus. Phosphorus has an atomic number of 15, meaning it has 15 protons in its nucleus. The number 31 indicates the mass number, which is the total count of protons and neutrons in the nucleus. Therefore, 31P has 15 protons and 16 neutrons (31 - 15 = 16). This specific isotope is naturally occurring and makes up virtually 100% of all elemental phosphorus found on Earth. It is a non-radioactive isotope, meaning it does not undergo radioactive decay. This stability is crucial for its widespread presence in biological systems and its use in various industrial and chemical applications. 31P plays a vital role in life, being a fundamental component of DNA, RNA, ATP (adenosine triphosphate), and phospholipids, which are essential for cell membranes. In scientific research, 31P nuclear magnetic resonance (NMR) spectroscopy is a powerful technique used to study the structure and function of molecules containing phosphorus.