For an experiment, a biology student makes 1 liter of a solution containing the substances shown in the table below. Using the given information, fill in the missing parts of the table for each substance by (a) providing the formula weight and (b) calculating either the mass the student needs to weigh out or the number of moles that the student has, based on the amount weighed out. For each calculation, show your work. Be sure to include the formula mass of water for CaCl2 • 2H2O and Na(CH3)2 AsO2 • 3H2O.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.

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.

yes the answer is total mass in unchanged   : )