The SI unit for mass is the kilogram, abbreviated as ‘kg’. This unit is part of the International System of Units (SI), which is a standardized system of measurement used globally in science, industry, and everyday life.
The kilogram is defined by the physical mass of a specific prototype: a platinum-iridium cylinder known as the International Prototype of the Kilogram (IPK), which was kept at the International Bureau of Weights and Measures (BIPM) in France until 2019. More recently, the kilogram was redefined in terms of fundamental constants. Since May 20, 2019, it is defined using the Planck constant, which is a fundamental constant of quantum physics. This redefinition ensures greater stability and precision in measurements.
Historically, mass was measured using other units such as grams and pounds, but the kilogram is now recognized as the base unit of mass in the SI system. For context, one kilogram is equal to 1,000 grams. This makes it a convenient unit for measuring the mass of various objects, from small items like food products to larger ones like machinery.
In conclusion, when referring to mass in scientific and technical contexts, the kilogram is the standard unit used to ensure consistency and accuracy in measurements across various fields, including physics, chemistry, engineering, and more.