Which one of the following order represents the correct sequence of the increasing basic nature of the given oxides?

Options

A. `MgO lt K_2O lt Al_2O_3 lt Na_2O`
B. `Na_2O lt K_2O lt MgO lt Al_2O_3`
C. `K_2O lt Na_2O lt Al_2O_3 lt MgO`
D. `Al_2O_3 lt MgO lt Na_2O lt K_2O`

Answer

D

Explanation

Metallic character decreases across a period in the sequence as Na, Mg, Al and increases down the group in the sequence as Na, K. As metallic character of the element attached to oxygen atom increases, the basic character of oxides increases. Hence, the increasing order of basic nature is `Al_2O_3 lt MgO lt Na_2O lt K_2O`