Which block elements in the modern periodic table are the least electropositive?

Which one of the following reactions does not occur?

In which of the following are the oxides of three elements $X, Y$ and $Z$ correctly arranged in the increasing order of acidic nature? The electronic configurations of $X, Y$ and $Z$ are $[Ne] 3s^2 3p^1$,$[Ne] 3s^2 3p^5$,and $[Ne] 3s^2$ respectively.

Considering the elements $B, C, N, F,$ and $Si,$ the correct order of their non-metallic character is:
$(a)$ $B > C > Si > N > F$
$(b)$ $Si > C > B > N > F$
$(c)$ $F > N > C > B > Si$
$(d)$ $F > N > C > Si > B$

The correct order of relative basic character of $NaOH$,$Mg(OH)_2$ and $Al(OH)_3$ is

The correct order of the metallic nature of the following elements is