Which of the following pairs has elements containing the same number of electrons in the outermost orbit?

Red hot carbon will remove oxygen from the oxides $XO$ and $YO$ but not from $ZO$. $Y$ will remove oxygen from $XO$. Use this evidence to deduce the order of activity of the three metals $X, Y$ and $Z$ putting the most active first.

An element $A$ dissolves in both acid and alkali. It is an example of

How do you determine the chemical reactivity of a compound? Provide an example.

The correct set that contains all kinds (basic, acidic, amphoteric, and neutral) of oxides is:

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