What is the abbreviation for microgram?

The abbreviation for microgram is commonly represented as "mcg." This designation stems from the metric system and reflects the international standard for measuring very small quantities, particularly in fields such as medicine and pharmacology.

Specifically, "micro" denotes a factor of one millionth, or 10^-6, meaning that one microgram is one-millionth of a gram. This unit is extensively used in medical dosages and laboratory measurements where precise calculations are paramount, such as in the administration of medications or the measurement of biological substances.

The other abbreviations provided represent different units of mass: "g" stands for gram, "kg" stands for kilogram, and "F" does not correspond to any recognized unit of mass in this context. By understanding these prefixes and their meanings, it's clearer why "mcg" is the standard abbreviation for micrograms.