.
Anyone learning / studying Science must know that
1 liter ow water has a mass approximately 1 kilogram.
By knowing this fundamental fact, you can easily determine the mass of half-liter water volume.
Happy learning !
Come again soon to learn something new !
P.S. 1 kilogram = 1000 grams.
/\/\/\/\/\/\/\/
On water density, see these links
https://www.usgs.gov/special-topic/water-science-school/science/water-density
https://hypertextbook.com/facts/2007/AllenMa.shtml
https://www.sciencelearn.org.nz/resources/1009-water-density
It is really interesting.
For example, do you know that one of the reasons/causes why the life does exist on Earth is in that water density
has inversion at the temperature near 4 degrees of Celsius ?