Nitrogen is a colorless and odorless gas at room temperature and a chemical element represented by the symbol N and atomic number 7. It makes up the largest volume of the air (about 78.1%) on Earth and is an essential building block of amino acids and nucleic acids (DNA and RNA). This means that nitrogen is essential to life! There are two stable isotopes of nitrogen and both are found naturally on Earth. However, there are a number of other isotopes of nitrogen that have been discovered. Let’s find out how many isotopes nitrogen have been identified.
How many isotopes does nitrogen have?
The two stable isotopes of nitrogen are nitrogen-14 (14N) and nitrogen-15 (15N). The vast majority of nitrogen found on Earth is N14 and it makes up about 99.636% of all natural nitrogen on the planet. It is believed to be formed in the CNO cycle in stars. N15 is a rare stable isotope of nitrogen (just 0.00364% of natural nitrogen). Despite being rare, it has some important uses such as medical research.
Fourteen unstable (radioactive) isotopes of nitrogen have also been identified. All of these isotopes have relatively short half lives and the longest is N13 at just under 10 minutes. All of the remaining isotopes have a half life of less than 7.15 seconds and most are below a second. The shortest half life of any nitrogen isotope to have been discovered is nitrogen-10, which has a half life of just 2.3 microseconds. The majority of the isotopes with an atomic mass of less than 14 decay to carbon isotopes and the isotopes with masses over 15 mostly decay to oxygen isotopes.