Chapter 2, Problem 3CT

Polonium is a rare element with 33 radioisotopes. The most common one, ²¹⁰Po, has 82 protons and 128 neutrons. When ²¹⁰Po decays, it emits an alpha particle, which is a helium nucleus (2 protons and 2 neutrons). ²¹⁰Po decay is tricky to detect because alpha particles do not carry very much energy compared to other forms of radiation. They can be stopped by, for example, a sheet of paper or a few inches of air. This property is one reason why authorities failed to discover toxic amounts of ²¹⁰Po in the body of former KGB agent Alexander Litvinenko until after he died suddenly and mysteriously in 2006.

What element does an atom of ²¹⁰Po decay into after it emits an alpha particle?