Since 1889, Le Grand K, a sleek cylinder of platinum-iridium metal, has ruled from its underground vault in Paris. An absolute monarch, it was the very definition of 1 kilogram of mass. Scientists ...

Grams (g) and kilograms (kg) are used to describe measurements of mass. Grams are used for smaller or lighter items. 1,000 grams are equal to 1 kilogram. You can write it like this: 1,000 grams = 1 ...