Describe the makeup and arrangement of a neutral atom of lead-209.
A nucleus of lead-209 emits a beta-particle. State how the nucleus formed is different in composition from the original nucleus.
Complete the table in Fig. 11.1 to show the relative ionising effects of the three kinds of ionising radiation emitted in radioactive decay.
A sample containing lead-209 nuclei is used to generate a beam of beta-particles. The beta-particles pass into a magnetic field. The magnetic field is at right angles to the direction of travel of the beta-particles. The beta-particles move from left to right. Fig. 11.2 shows that the magnetic field is directed out of the page. On Fig. 11.2, sketch the path of the beta-particles in the magnetic field.
State what is meant by background radiation.
Suggest two major sources of background radiation.
The technician records an average background count of 16 counts per minute. He then brings a sample containing a radioactive isotope of lead close to the detector and finds that the count rate rises to 92 counts per minute. This isotope has a half-life of 3.3 hours. Determine the count rate measured with the detector after 6.6 hours.