Which factor causes a decrease in the rate of dissolution?
decreasing the amount of solute
increasing the stirring of the solution
decreasing the surface area of the solute
increasing the temperature of the solvent

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;

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.