トリウム系けい列れつ

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リ

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ム

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Meanings

1

noun

thorium series

chemistry

In nuclear chemistry, the radioactive decay chain starting from thorium-232 and ending with lead-208.

ウラン系けい列れつ
The uranium series starts from uranium-238, while the thorium series starts from thorium-232.
アクチニウム系けい列れつ
The actinium series starts from uranium-235, another natural decay chain.

Compound of トリウム (thorium) and 系列 (series, lineage). The term is a direct calque from English 'thorium series', used in nuclear chemistry.