Chlorine-37
Chlorine-37 is a stable isotope of the element chlorine, which has an atomic number of 17. It accounts for about 24% of naturally occurring chlorine. Chlorine-37 has 20 neutrons in its nucleus, giving it a mass number of 37.
This isotope is commonly used in various applications, including nuclear magnetic resonance (NMR) spectroscopy and as a tracer in environmental studies. Its stability makes it useful for research, as it does not undergo radioactive decay like some other isotopes of chlorine.