The International System of Units (SI) is a modern, scientific method of articulating quantities and magnitudes of important natural phenomenon. The system has seven base units from which other units are derived. The SI units are either expressed directly or as standard multiples. According to Cohen et al (54), The SI system has three main models.
1) It has seven fundamental or dimensionally independent units that are irreducible by any convection. They include the meter, kilogram, ampere, Kelvin, candela, second and the mole.
2) The SI system of measurement has a large number of units derived from fundamental units based on the algebraic relations of the equivalent quantities. Some of these derived units have special symbols and names that can be combined to form more derived units. The derived units are complete units because only one derived unit exists for any given physical quantity.
3) The system also has twenty prefixes that can be assigned to any fundamental units or their derived units. These prefixes have some special names that create multiples and divisions, as they are needed.
The SI unit is not a static system. Some prefixes and units are added, and the definitions of the units altered through some international agreements as the measurement technology evolves for greater precision. SI unit system of measurement is one of the mostly widely used measurement system used everyday not only in chemistry, but also in many measurements in science and technology (Cohen et al 64).
This method has been adopted by many countries as their measurement system. It has many advantages over other systems of measurement. The system has no conversions because only one unit exists for each quantity. The system does not require memorization because all the derived units are defined without their numerical factors. It also does not have fractions and it is complete because it can measure any physical quantity. It also a world standard measurement accepted by many countries. The SI system of measurement is coherent, has clear symbols and has only 30 symbols as compared to the hundreds of non-SI units. The main disadvantage of SI units is that the system uses decimals only in measurement meaning it is not suited for use while working with fractions (Ian et al, 55).
Works cited.
Cohen, Erick et al. Quantities, units, symbol’s in physical chemistry. Cambridge: RHS
Publishing. 2007.
Ian, Mills et al .Quantities, units and symbols in physical chemistry. 2nd edition. Edinburg:
Blackwell publishers.1993.
