what unit of mass is 1/1000 of a kilogram
Kilogram The gram, 1/1000 of a kilogram, was provisionally defined in 1795 as the mass of one cubic centimetre of water at the melting point of ice.[4] The final kilogram, manufactured as a prototype in 1799 and from which the International Prototype Kilogram (IPK) was derived in 1875, had a mass equal to the mass of 1 dm3 of water under atmospheric pressure and at the temperature of its maximum density, which is approximately 4 °C.
Calorie Although these units relate to the metric system, all of them have been considered obsolete in science since the adoption of the SI system.[3] The unit of energy in the International System of Units is the joule. One small calorie is approximately 4.2 joules (so one large calorie is about 4.2 kilojoules). The factor used to convert calories to joules at a given temperature is numerically equivalent to the specific heat capacity of water expressed in joules per kelvin per gram (or per kilogram, for kilocalories). The precise conversion factor depends on the definition adopted.