Nitrogen-14 is a stable isotope of the element nitrogen, which has an atomic number of 7. It consists of 7 protons and 7 neutrons in its nucleus. Nitrogen-14 makes up about 99.6% of naturally occurring nitrogen, which is essential for life and found in proteins and nucleic acids. This isotope plays a crucial role in the nitrogen cycle, a natural process that recycles nitrogen in various forms through the environment. Nitrogen-14 is also used in scientific research, including radiocarbon dating, to help determine the age of organic materials.