Neon

In nature, neon is found in the Earth's atmosphere, 18.2 ppm (v/v), and in igneous rocks, 7 · 10⁻⁵ ppm (w/w) [3]. The isotopes found in nature are ²⁰Ne (90.51 %, stable), ²¹Ne (0.24 %, stable) and ²²Ne (9.92 %, stable) [3].