Definitely definite mass because liquids can take on any shape and can have different volumes.
Tap water and rain water are both homogeneous, even though they may have different levels of dissolved minerals and gases. A bottle of alcohol is a man-made homogeneous mixture, from a fine Italian wine to a glass of Scotch whisky. In the human body, blood plasma is an example of a homogeneous mixture.
2H2 (g) + O2 (g) -->2H2 O(g)
mole ratio of H2:O2=2:1
7.25/2=3.625
Jellyfish aren't necessarily bad or do bad things humans do find that the tentacles that happen to "shock" or "electructe" people are bad. As well as the way jellyfish live in one grouping it is rare but you can find jellyfish out of a group, they do this that way they can eat and stay away from predators.
I hope this helped you!
Graduated cylinder
Stopwatch
Thermometer