What is the importance of color in the periodic table?
a. to identify families, elements with similar properties.
b. to show which elements have greater atomic mass.
c. to indicate identical elements.
d. to separate acids and bases.

Color is used in the periodic table to facilitate the visual identification of families which are elements with similar properties that are placed in the same column. For example, one color for alkalyne metals (column one), other color for alkalyne earth (column two), other color for halogens (column 17), other color for noble gases (column 18). So the answer is the option A, to identify families, elements with same properties.