Answer: Polar molecules
Explanation: Water is able to dissolve many substances because of its polar molecules, The positive and negative ends of a water molecule attracts the molecules of other polar substances..
I'm pretty sure, idk college stuff
Density = mass / volume
Density = (45g) / (9 [volume units])
Density = 5g / [volume unit]
There was no specification on the units of volume. However, whatever it may be, just replace the square brackets with the value and your units will be correct.
2.5X20=50g
50g should be the right answer
Mass=volumeXdenisty.