Unit prefixes are the symbols placed before the symbol of a unit to specify the order of magnitude of a quantity. They are useful to express very large or very small quantities. k(kilo) is the unit prefix in the unit, kilogram. A unit prefix stands for a specific positive or negative power of 10. k stands for 1000 or 103. Some unit prefixes are given in Table-6.
The physical quantities vary in different proportion like from 10-15 m being the diameter of nucleus to 10-26 m being the distance between two stars and 9.11 × 10-31 kg being the electron mass to 2.2 × 10-41 kg being the mass of the milky way galaxy.