In chemistry lab, Michael made 142.5 mL of an acid solution using a mixture of 35.5 mL of a 69.5% acid solution and 107.0 mL of a 24.9% acid solution. Calculate the percent concentration of the acid mixture Michael made.

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.