A 20.00-mL sample of hard water (with Mg2 added) is titrated with 0.0105 M EDTA. A blank solution with the same amount of Mg2 requires 2.35 mL of EDTA to reach its end point. A total of 34.13 mL of EDTA was used for the titration of the 20.00-mL sample of hard water (with Mg2+ added). M. W. CaCO3= 100.1 g/mol. Requried:
a. How many moles of EDTA are rquired to titrate the Ca²+ present in the 20.00-mL sample?
b. Assuming that Cat is present as Cacos, how many grams of CaCO3 are there in 20.00 mL of hard water?
c. What is the concentration of CaCO3 in parts per million?

hi my dude or dudette

that's what i got you can count the number of atoms

elements make up everything, and they combine to make compounds.

the answer is c

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.