Explain the comparative study including diagonally relationship of group 16 to 17 elements

16th group elements have large size than 17th group elements. 2nd ionisation enthalpy of 16th group elements is greater than the 17 group elements. 17th group elements have high negative value of electron gain enthalpy than 16th group elements because they require only one electron to attain nearest noble gas configuration. 17th group elements are more electronegative than 16th group elements. And in diagonal relationships 1st member of 16th group have some properties similar to that of the second member of 17group.