Chemical compound in which a radioactive isotope is substituted for a stable one. The path taken by such a compound through a system can be followed, for example by measuring the radiation emitted.
This powerful and sensitive technique is used in medicine, chemistry, biochemistry, and industry.
Green represents the Islamic minority. Orange stands for the Hindu Tamils. The sword denotes authority. The four pipul leaves symbolize Buddhism. Effective date: 7 September 1978.