Neon (10Ne) possesses three stable isotopes: 20Ne, 21Ne, and 22Ne.
In addition, 17 radioactive isotopes have been discovered, ranging from 15Ne to 34Ne, all short-lived.
The longest-lived is 24Ne with a half-life of 3.38(2) min.
See isotopes of carbon for notes about the measurement.
Light radioactive neon isotopes usually decay to fluorine or oxygen, while heavier ones decay to sodium.