The basis of keeping the elements in the same group of a periodic table is

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.

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

$Be$ and $Al$ show similarities in properties due to the diagonal relationship except in the property $X$ given below. What is $X?$

The electronic configuration of three elements $A, B$ and $C$ are given below. The molecular formula of the compound formed from $B$ and $C$ will be
$A : 1s^2, 2s^2, 2p^6$
$B : 1s^2, 2s^2, 2p^6, 3s^2, 3p^3$
$C : 1s^2, 2s^2, 2p^6, 3s^2, 3p^5$

Which of the following is an amphoteric oxide?