15 points for only two question : )
how does electron shielding affect atomic size as you move down a group?
and
explain why noble gases have high ionization energy?

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

The molality of calcium chloride (cacl2) in an aqueous solution is 2.46 m. what is mole fraction of the solute?