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Before 2019 what was Le Grand K?

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Before 2019 what was Le Grand K?
posted May 8 by Simranjeet Singh

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The object which defined the magnitude of the mass of the kilogram
Le Grand K was established in 1889 (replacing two earlier definitions for the kilogram) and stored in Saint Cloud, France; it is a roughly golfball-sized object, 90% platinum and 10% iridium by mass. It was replaced in 2019 by definition in terms of three fundamental physical constants: the speed of light, a specific atomic transition frequency, and the Planck constant.

answer May 9 by Samardeep Acharya
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