Question: what is the difference between g and gm?
Answer: The gram (abbreviation, g or gm) is the cgs (centimeter/gram/second) unit of mass. ... A mass of one microgram (1 µg) is 10-6 g. A mass of one nanogram (1 ng) is 10-9 g. In the International System of Units (SI), the kilogram is the preferred unit of mass.