Scientists from around
the world use one set of units to communicate information. This set of units
is known as the International System of Units, or more commonly referred to
as the SI system.

There are many SI
base units of measurements. For this course, we will concentrate on the
5 base units listed below:

For a measurement
of MASS, the base unit is kilogram.

For a measurment of LENGTH,
the base unit is meter.

For a measurement of
VOLUME**, the base unit is liter.

For a measurement of
TIME, the base unit is second.

For a measurement of
TEMPERATURE, the base unit is kelvin.

**
The base units of length and volume are connected in the SI system. By definition, a liter is equal to the volume of a cube exactly 10 cm in length, 10 cm width, and 10 cm height. Because the volume of the cube is 1000 cm^{3} and a liter contains 1000 milliliters, 1 milliliter is equivalent to 1 cm^{3}.

1 mL = 1cm^{3}

The gram was originally defined as the mass of 1 mL of water at 4 ^{o}C.