<P> The periodic table is a tabular arrangement of the chemical elements , ordered by their atomic number , electron configuration , and recurring chemical properties . This adopted ordering shows periodic trends , such as elements with similar behaviour in the same column . It also shows four rectangular blocks with some approximately similar chemical properties . Generally , within one row ( period ) the elements are metals on the left , and non-metals on the right . Table rows are called periods and columns are called groups . Six groups have accepted names as well as assigned numbers : for example , group 17 elements are halogens ; and group 18 are noble gases . </P>
what do the columns and rows on the periodic table represent
rows are called periods and columns are called groups