A kilogram.
The gram.
In the SI - the current metric system - that would be the kilogram. In older metric systems, the gram has been used as the unit of mass.
The kilogram is the official unit of mass.
Carat IS a metric unit of mass
Mass.
kilograms
The metric standard unit of mass is the kilogram (Kg).
Grams.
Kilogram
The kilogram.
The gram.
The SI (metric) unit for mass is the kilogram.
Pounds.
The SI unit for mass in the metric system is the kilogram.
A neutron is an electrically neutral subatomic particle. A Newton is the metric unit of force. A Kilogram is the metric unit of mass. We have no idea what a 'newtron' is.
Grams. Matter is measured by mass and mass's main unit is grams.
The SI unit of mass is the Kilogram.