Which of the following is the most electropositive element?

Which of the following sets has the strongest tendency to form anions?

Which of the following elements is considered as a metalloid?

The first member of each group of representative elements (i.e.,$s$- and $p$-block elements) shows anomalous behaviour. Illustrate with two examples.

The correct order of acidic strength is:

With the help of the following reactions,arrange metals $A$,$B$,$D$,and $E$ in decreasing order of their reactivity:
$(I)$ $B + ANO_3 \to BNO_3 + A$
$(II)$ $A + HCl \to ACl + \frac{1}{2}H_2$
$(III)$ $D + ECl \to DCl + E$
$(IV)$ $D + HNO_3 \to H_2$ gas is not evolved