Explain dissolving, and express how boiling can reverse the process in the example of salt water

Explanation:

Dissolving is when a soluble solute is added to a solvent. The solvent surrounds the solutes and makes a solution of it. The process of dissolving is known as dissolution. For a substance to be able to dissolve in a solvent, they must both have similar properties. It is generally known that like dissolves like. Polar solvents will dissolve polar solutes and vice versa.

Boiling can reverse dissolution process in that, the solvent can reach its boiling point and it wil begin to give out vapours. As more vapours are release, the solutes begin to aggregate and form back.

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.