metric system
what does liter mean
a metric unit of capacity
volume
what is a Millimeter
what is volume
the amount of space that a substance or object occupies, or that is enclosed within a container, especially when great.
what is a gram
The gram is a unit of mass in the International System of Units equal to one thousandth of a kilogram.
Density
the relationship between the mass of the substance and how much space it takes up (volume