Isotopes of thallium (source code)

= Isotopes of thallium
{wiki=Isotopes_of_thallium}

Thallium (Tl) has several isotopes, which are variants of the element with the same number of protons but different numbers of neutrons. Naturally occurring thallium has two stable isotopes: 1. **Thallium-203 (Tl-203)**: - Number of protons: 81 - Number of neutrons: 122 - Natural abundance: About 29.5%.