Thallium-201 is used in cardiac imaging. It decays by electron capture. What isotope is produced when thallium-201 captures an electron?
A)thallium-202
B)lead-201
C)lead-202
D)mercury-201
E)mercury-202

Question

Quizplus · Accepted Answer

When thallium-201 undergoes electron capture, it transforms into mercury-201. This process involves the capture of an inner orbital electron by the nucleus, which decreases the atomic number by one, changing thallium (atomic number 81) to mercury (atomic number 80).

Thallium-201 Is Used in Cardiac Imaging