Arrange the following elements in the order of their decreasing metallic character Na, Si, Cl, Mg, Al

The correct option is B Na >Mg >Al >Si > Cl
Metallic character decreases across a period as the number of valence electrons increases. Metals lose electrons to attain the octet. Na has only 1 valence electron hence it will lose it most easily and s it is the most metallic element. Mg has 2, Al has 3, Si has 4 and Cl has 7 valence electrons respectively. So there is a decrease in the metallic character.