Kilograms for a row boat but a ton for larger vessels.
Gram.
The metric (SI) unit for weight is the newton, since weight is a force. When people talk about "weight", they sometimes actually mean "mass". The unit for mass is the kilogram.
Tonnes
Gram.
a ruler
Meters
grams
The metric standard unit of mass is the kilogram (Kg).
The gram is a metric unit of mass.
The basic metric unit of mass is the gram (g).
Milligrams.
The SI unit for mass in the metric system is the kilogram.
The basic unit of mass in the metric system is the gram.
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.
The SI (metric) unit for mass is the kilogram.
The base unit of mass is the kilogram.
An appropriate metric unit of mass for a pencil would be grams.