The location of an element in the periodic table reflects

Example: 

Na (Z = 11) has electronic configuration $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^1.$ The last orbital stands as $3{\mathrm{s}}^1$ which is related to position of sodium in periodic table as: 3rd period, s-block and 1st group.