What would the mass be for 500 ml of water?

The density of water is about 1.00 g/ml, so 500 ml of  water is about 500 g 

Atomicity occurs to prevent updates of the database occurring only partially, which can cause greater problems than rejecting the whole series outright.some are monatomic, diatomic, triatomic etc because it shows the number of atoms. for example, monatomic means it contains only one atom.

The answer is probably c. xylem