Answer:
c 18.0ml
Explanation:
The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.
 
        
             
        
        
        
The density of marble is between 2.6 and 2.8 grams per cm³ .
Density doesn't depend on how much mass or volume of it you have.
The density of a chip of it is the same as the density of a truckload of it.
        
             
        
        
        
Answer:
B
Explanation:
Planting trees sequesters CO2
   all of the other choices produce more CO2 in the atmosphere
 
        
             
        
        
        
To find the mass of the water, you will first need to find the mass of a dry 100 mL beaker.-------51.377g 
<span>Next, find the mass of the 100 mL beaker containing your water sample. ------------------------ 101.23g  hope this helps :()</span>
        
             
        
        
        
Milliequivalent is a unit that made from millimol unit multiplied by the valence of the atoms. Calcium has 2 valence electron so the mEq would be twice as much as the mol. The solution has 155meq/liter and the volume is 1850ml. Then, the amount of calcium in the solution should be:
1850ml * (155mEq/1000ml) / (2mEq/mmol)= 143.375mmol= 0.144 mol