Which of the following is equivalent to 1 liter?

1 liter is equivalent to 1000 milliliters (mL), which is a standard conversion in the metric system. This relationship is based on the fact that 1 liter is defined as the volume of a cube that measures 10 centimeters on each side. Since 1 mL is defined as 1 cubic centimeter (cm³), this means that 1 liter, which is 1000 cm³, translates directly to 1000 mL. Therefore, choosing 1000 mL accurately reflects the volume in milliliters that corresponds to 1 liter.

The other options do not reflect the correct conversion to liters. 100 mL and 500 mL represent fractions of a liter, while 1.5 L exceeds the amount in question. Thus, only 1000 mL represents the full equivalent of 1 liter.