Question

How many stable isotopes does nitrogen have?

Answer 1

The variants in a particular chemical element having different atomic masses (due to different neutron numbers) but the same atomic number are known as isotopes. We know that stable isotopes are those which can exist easily and nitrogen has only 2 isotopes which are stable and rest are unstable (as their half-lives are very short).

Complete answer:
Generally isotopes are the variants of a single chemical element with different atomic masses but the same atomic number as their number of neutrons is different but protons remain the same.
-Stable isotopes are those types of variants which are non-radioactive forms of an atom i.e., they do not emit radiations but their unique properties enable them to be used in a broad variety of applications such as water and soil management, environmental studies, nutrition assessment studies and forensics.
-Nitrogen is an element of the pnictogens group (group-15) with atomic number as 7. Nitrogen has 16 isotopes out of which only 2 are stable isotopes and rests 14 are radioisotopes.
-The 2 stable isotopes of nitrogen are as follows:
Nitrogen-14 ($^{14}N$ ): It is one of the 2 stable isotopes of element nitrogen and it makes about 99.636% of the total natural nitrogen. It is one of the very few stable nuclides with an odd number of protons and neutrons (7 each) and is the only one to make up a majority of its element. It is also the source of a naturally occurring radioactive element which is carbon-14.
Nitrogen-15 ($^{15}N$): It is a rare but stable isotope of nitrogen. Its sources are the positron emission of oxygen-15 and the beta decay of carbon-15. Nitrogen-15 is also used in NMR (Nitrogen-15 NMR spectroscopy). Nitrogen-15 tracing technique is very useful and helps to study the nitrogen cycle.
Hence the two stable isotopes of Nitrogen are: $^{14}N$ and $^{15}N$

Note:
All of these radioisotopes of Nitrogen are short-lived, among which nitrogen-13 (a synthetic isotope) is the longest lived with a half-life of 9.965 minutes. Rest has half-lives below 7.15 seconds and most of these being below 620 milliseconds.
-Most of the isotopes of Nitrogen with atomic mass numbers below 14 decay to isotopes of carbon, while above 15 decay to isotopes of oxygen.