* Neon-20 (²⁰Ne): The most abundant isotope, making up about 90.48% of natural neon.

* Neon-22 (²²Ne): The second most abundant isotope, representing around 9.25% of natural neon.

* Neon-21 (²¹Ne): The least abundant of the three, making up about 0.27% of natural neon.

While there are other, less common isotopes of neon, these three are the ones you'll encounter most often.