Question

Question 17
Arrange the following elements in the order of their decreasing metallic character
Na, Si, Cl, Mg, Al

(a) Cl > Si >Al > Mg >Na
(b) Na >Mg >Al >Si > Cl
(c) Na > Al > Mg > Cl > Si
(d) Al > Na> Si > Ca> Mg

Answer 1

Option (b) is correct.
Metallic character decreases across a period as the number of valence electrons increases. Metals readily lose electrons and nonmetals readily gain electrons to attain the nearest noble gas electronic configuration. All the given elements belong to period 3.
Na has only 1 valence electron hence it will lose it most easily and 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 from Na to Cl.