PART B: RADIOISOTOPES
Radioactivity is the spontaneous emission of energy from unstable atoms.
Atoms are found in all natural matter. There are stable atoms, which remain the same forever, and unstable atoms, which break down or 'decay' into new atoms. These unstable atoms are said to be 'radioactive', because they emit radioactivity from the nucleus as they decay.
Radioactive elements, such as uranium, thorium and potassium break down (decay) fairly readily to form lighter atoms. The energy that is released in the process is made up of small, fast-moving particles and high-energy waves. These particles and waves are, of course, invisible. (The level of radioactivity of an element varies according to how stable its atoms are). Other elements with naturally occurring radioactive forms, (isotopes) are carbon, bismuth, radon, and strontium.
Radioactivity is a random process that happens naturally as the isotopes in particular elements decay. The isotopes continue to break down over time. The length of time that is taken for half of the nuclei in an element to decay is called its 'half-life'. A half-life can be very short (milliseconds to hours) or very long (hundreds of thousands of years).
Sodium-24 is commonly used for finding leaking pipes in industry field.
Sodium-24 is an industrial tracer used by industrial radiologists to find leaking pipes. It is a beta emitter meaning that the radioactive particle is a neutron, as a result it has moderate penetrating power and low ionizing power so small amounts are relatively safe. In the pipe the radiation will be shielded by the pipe material so any leaks causing the tracer to become exposed can be indicated by a geiger or scintillation counter. Also since Na-24 has a 15 hr half life it is quickly decomposed to a more stable isotope and hence has a lower effect on the surrounding environment when the tested pipe is washed out to remove the tracer.
The most rapid contribution which atomic energy makes to the...