The measurement of mass is usually kg(kilograms) for large masses and g(gram) for small masses.The word kilo means 1000 so it's just another way to say 1000 grams. You can also use mg(milligrams). Mill means thousandths. So if you put that in a decimal it would be 0.001. So a 1000mg=1 gram.
Density is units of mass per unit of volume.
Units of measurement provide a standard to measure mass, length etc.So, it is useful.
gram
Kilograms
It doesn't make sense to convert units that measure completely different things. You can only convert units of length to units of length, units of mass to units of mass, etc.
Grams
Tape measure
Units of measure are used to measure anything: length or volume, mass or speed, pressure or force etc.
Kilograms.
kilograms
Grams
grams or other units
The international unit for mass is the kilogram.
AMU=Atomic Mass Unit
descibe the tundra
kilograms
Pounds