4. What are the respective concentrations (M) of Cu+2 and Cl' afforded by dissolving 0.200 mol CuCl2 in water and diluting to 345 mL?
A) 0.200 and 0.200
B) 0.580 and 1.16
C 0.200 and 0.400
D) 1.16 and 2.32
E 0.580 and 0.290

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.