6.1 Radioactive Substances
1.   Radioactive substances are substances with unstable nuclei in their atoms. Unstable nuclei will decay and emit radioactive radiation.
2.  Examples of radioactive substances are:
(a) Carbon-14
(b) Cobalt-60
(c) Iodine-131
(d) Uranium
(a) Carbon-14
(b) Cobalt-60
(c) Iodine-131
(d) Uranium