The half-life of radioactive elements test questions - WJEC


Radioactive materials decay naturally and release alpha, beta or gamma radiation. What is the name given to the number of nuclei that decay each second?


What is a becquerel?


What is the half-life of a radioactive isotope?


Which of the following radioactive isotopes would be most suitable as a tracer to monitor blood flow in a patient’s heart?


A radioactive source’s activity falls from 8,000 counts per minute to 500 counts per minute in 20 hours. What is the half-life of the source?


Which of the following isotopes would be used in a machine for measuring paper thickness?


What percentage of an original polonium sample will remain after three half-lives have passed?


Wood from a sample of carbon-14 in a living tree has an activity of 120 Bq. Wood found in an archaeological dig has an activity of 30 Bq. The half-life of carbon-14 is 5,730 years. Estimate the age of the dead wood.


An internal cancer is treated by injecting a small quantity of a radioactive isotope directly into the cancer. What isotope should be used?


In a cereal factory the filling of cereal into a cardboard box is measured with a radioactive source that is placed just below the top. When the cereal reaches it, the count rate at the other side is significantly reduced, stopping the filling process. What should the radioactive source be?