Element:Th

Thorium was discovered in 1828 in the mineral thorite by Jons Berzelius. Its name comes after Thor (Scandinavian god of war). It is mildly radioactive and has 10 isotopes. Naturally occurring ²³²Th goes 10 decay steps before reaching stable lead ²⁰⁸Pb, and also emits thoron gas ²²⁰Rn.

Atomic Number

90

Atomic Name

Thorium(トリウム)

Stable Isotopes

isotope	mass	isotopic abundance (%)
232Th	232.0380495	100 = (Natural radioactivity isotope)

Radioisotopes

isotope	half life	disintegration form
228Th	1.9116 years	alpha
230Th	7.538 x 104 years	alpha
231Th	25.52 hours	beta-
232Th	1.405 x 1010 years	alpha
233Th	22.3 minuites	beta-