polly wrote:4000 grams of water hs a mass of -------------cubic litere
45 milliliters of water has a volume of ---- --------- -------
I'm hoping you made some mistakes in transcribing your homework. Otherwise, your teacher needs a course in remedial metric.
*The gram (or kilogram) is a unit of mass. 4000 g could be better expressed as 4 kg.
*The liter is a unit of volume, NOT a unit of mass. Water at maximum density (4 degrees C) just happens to be 1 L/kg, so this is also about 4 L.
As liters are already a unit of volume, there is no such thing as a "cubic liter." However, a liter is equal to a cubic decimeter, a cube 1 dm x 1 dm x 1 dm.
45 mL of water has a volume of a 45 mL of water. I suppose you could also say 0.045 L or 45000 uL; while both numbers would be mathematically correct, they are not convenient and are discouraged. 45 mL of water would have a mass of about 45 g.
For a substance other than water, having a density different from 1 kg/L, understanding the difference between volume and mass is critically important.