Isotopes of lanthanum

Naturally occurring lanthanum (₅₇La) is composed of one stable (¹³⁹La) and one radioactive (¹³⁸La) isotope, with the stable isotope, ¹³⁹La, being the most abundant (99.911% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being ¹³⁸La, with a half-life of 1.03×10¹¹ years; ¹³⁷La, with a half-life of 60,000 years and ¹⁴⁰La, with a half-life of 40.289 hours. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these less than a minute. This element also has 12 nuclear isomers, the longest-lived of which is ^132mLa, with a half-life of 24.3 minutes. Lighter isotopes mostly decay to isotopes of barium and heavy ones mostly decay to isotopes of cerium. ¹³⁸La can decay to both.

The known isotopes of lanthanum range from ¹¹⁶La to ¹⁵⁵La.

Daughter products other than lanthanum