The half-life of ²³⁵U, an alpha emitter, is 7.1⨉10⁸ years. Calculate the number of alpha particles emitted by 1.0 mg of this nuclide in 1.0 minute.

Half-life is the time required for half of the radioactive nuclei in a sample to decay. For uranium-235, which has a half-life of 7.1 × 10^8 years, this means that after this period, only half of the original amount of uranium-235 will remain, while the other half has transformed into other elements through radioactive decay.

Radioactive decay is the process by which unstable atomic nuclei lose energy by emitting radiation, such as alpha particles. In the case of uranium-235, it decays by emitting alpha particles, which consist of two protons and two neutrons, effectively reducing the atomic number and mass of the original nucleus.

The activity of a radioactive sample is defined as the number of decays per unit time, typically measured in becquerels (Bq). To calculate the number of alpha particles emitted by a sample, one can use the activity formula, which incorporates the number of radioactive atoms present and the decay constant derived from the half-life, allowing for the determination of emissions over a specified time frame.