kilogrammjának

The term "kilogrammjának" appears to be a misspelling or a non-standard variation. The standard international unit for mass is the kilogram, symbolized by "kg". The kilogram is the base unit of mass in the International System of Units (SI). It is defined by fixing the numerical value of the Planck constant, h, to 6.62607015 × 10⁻³⁴ J⋅s (joule-seconds). This definition was adopted on 20 May 2019, replacing the previous definition based on the international prototype of the kilogram.

Historically, the kilogram was defined as the mass of a specific physical object, the International Prototype of the Kilogram (IPK), a platinum-iridium cylinder housed in a vault near Paris. This artifact, along with its twelve official copies, served as the standard for mass for over a century. However, due to potential subtle changes in the IPK's mass over time, a more fundamental and stable definition based on a physical constant was deemed necessary for greater precision and universality.

The kilogram is a fundamental unit used in countless scientific, engineering, and everyday applications. It is used to measure the weight of objects, the amount of substances in chemical reactions, and the mass of materials in manufacturing. Prefixes from the SI system can be added to the kilogram to denote smaller or larger masses, such as the milligram (mg) or the megagram (Mg), also known as a tonne. The redefinition of the kilogram was a significant achievement in metrology, ensuring the unit's stability and accuracy for future generations.