How does the following equation demonstrate the law of conservation of mass? 22 + 2 → 22

Alarge marble is dropped in a graduated cylinder with 35ml of water in it.the water level increases to 49ml.what is the volume of the marble

Can someone me with 3 and 4 plz. this is for masteries test.

Need what is special about water as a compound? how does water regulate climate? what drives water evaporation?   why is the water vapor fresh water when it rises from the ocean? why might freshwater in the form of snow take longer to enter the water cycle again than liquid precipitation?   what is an aquifer? what role do people play in the water cycle? plz just answer as many as you can ! thx if you !