There Are Three Radioactive Series: the Thorium Series, Which Begins

question 77

Multiple Choice

There are three radioactive series: the thorium series, which begins with 232Th, the uranium series which starts with 238U and the actinium series which starts with what isotope?

• A) 235U
• B) 216Po
• C) 221Rn
• D) 214Pb
• E) 226Ra

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