Answer
Chemical and physical properties of the elements are more closely related to atomic numbers than they are to atomic weights because the atomic number tells you how many protons each element has.
Work Step by Step
This atomic number (the number of protons) relates to how many electrons an element has, and it is this electron configuration that determines an element's behavior and properties. While the atomic weight is similar to the atomic number, the atomic weight is not as consistent in determining the different behaviors of atoms.