In the lab, a chemist adds 3.6 grams of sodium chloride to 100.0 g of water. what is the molality of the solution?

0.616 m.

Explanation:

m = (no. of moles of solute)/(mass of the solvent (kg))

m = (mass/molar mass) NaCl / (mass of the solvent (kg))

mass of NaCl = 3.6 g, molar mass of NaCl = 58.44 g/mol, mass of water = 100.0 g = 0.1 kg.

m = (mass/molar mass) NaCl / (mass of the solvent (kg)) = (3.6 g / 58.44 g/mol) / (0.1 kg) = 0.616 m.

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.