Describe the nature of oxides formed by the extreme left elements of the s-block and elements on extreme right of the p-block

Elements on the extremes of a period easily combine with oxygen to form oxides. The normal oxide formed by the element in extreme left is the most basic (i.e., $N{{a}{2}}$0) whereas that formed by the element on extreme right is the most acidic (i.e., $C{{l}{2}}$${{O}{7}}$).
Oxides of elements in the centre are amphoteric (e.g., $A{{l}
{2}}$${{O}{7}}$, A{{s}{2}}$${{O}{3}}$) or netural (e.g., CO, NO, ${{N}{2}}$O).