Stone (US): While the stone is not commonly used in the United States, it is equivalent to 14 pounds (approximately 6.35 kilograms). In some contexts, people may refer to their weight in stones.
A femtogram (fg) is a metric unit of mass in the International System of Units (SI). It represents one quadrillionth of a gram or 10^-15 grams. The metric system is a decimal-based system of measurement used worldwide, and it is particularly useful for expressing extremely small quantities of mass.
To provide context for the size of a femtogram:
Femtograms are primarily used in advanced scientific and technical fields, particularly in situations where measuring the tiniest quantities of substances or particles is critical. Some common applications of femtograms include: