Polonium-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 55 mg of Po-218 (atomic mass = 218.008965 amu), how many alpha emissions occur in 25.0 minutes? If the polonium is ingested by a person, to what amount of radiation (in Ci) is the person exposed?

Half-life is the time required for half of the radioactive nuclei in a sample to decay. For Polonium-218, with a half-life of 3.0 minutes, this means that after 3.0 minutes, half of the original amount will have decayed. Understanding half-life is crucial for calculating the remaining quantity of a radioactive substance over time and determining the number of decay events that occur within a specified period.

Alpha decay is a type of radioactive decay in which an unstable nucleus emits an alpha particle, consisting of two protons and two neutrons. This process reduces the atomic number of the element by two, transforming it into a different element. In the context of Polonium-218, each decay event results in the emission of an alpha particle, which is essential for calculating the total number of emissions over a given time frame.

The Curie (Ci) is a unit of radioactivity that quantifies the rate of decay of radioactive materials. One Curie is defined as 3.7 x 10^10 disintegrations per second, which provides a measure of the intensity of radiation emitted by a radioactive source. When assessing the exposure to radiation from ingested Polonium-218, converting the decay events into Curie units helps quantify the potential health risks associated with the radiation exposure.