The quectogram measures mass at the extreme lower limit of the SI scale, representing 10⁻³⁰ grams or 10⁻³³ kilograms. This submultiple is essential in particle physics for expressing the mass of the lightest subatomic particles, such as electrons and neutrinos, without resorting to scientific notation. The symbol for this unit is qg.
Heard on the job
The electron mass is roughly 910 quectograms, making the math much cleaner on this blackboard.