Calculate the percent by mass of potassium nitrate in a solution made from 45.0 g KNO3 and 295 mL of water at 25 degrees Celsius. At this temperature, the density of water is 0997g/mL. A. 0.0468 M
B. 0.551 M
C. 0.214 M
D. 0.0311 M
E. 0.138 M

tracks, burrows, eggshells, nests, tooth marks, or gastroliths

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.