Which one of the following combinations represents a metallic element?

The characteristics of elements $X$,$Y$ and $Z$ with atomic numbers,respectively,$33$,$53$ and $83$ are :

The element with $Z = 120$ (not yet discovered) will be a/an:

In which of the following are the elements in the correct order of their chemical reactivity in terms of oxidizing property?

Arrange the acids $H_2SO_4$,$H_3PO_4$,and $HClO_3$ in the decreasing order of their acidic strength.

Considering the elements $B$,$Al$,$Mg$,and $K$,the correct order of their metallic character is:
$(a)$ $B > Al > Mg > K$
$(b)$ $Al > Mg > B > K$
$(c)$ $Mg > Al > K > B$
$(d)$ $K > Mg > Al > B$