The electronic configuration of an element is $1s^2, 2s^2 2p^6, 3s^2 3p^3$. What is the atomic number of the element which is just below the above element in the periodic table?

What is the correct order with respect to metallic property of $Zr, Cd, Sn, Sr$?

Based on the provided periodic table segment,identify the correct statement regarding the oxide of element $X$. The element with atomic number $Z = 52$ is Tellurium $(Te)$.

Among the statements $(I-IV)$,the correct ones are:
$(I)$ $Be$ has smaller atomic radius compared to $Mg$.
$(II)$ $Be$ has higher ionization enthalpy than $Al$.
$(III)$ Charge/radius ratio of $Be$ is greater than that of $Al$.
$(IV)$ Both $Be$ and $Al$ form mainly covalent compounds.

The following acids have been arranged in the order of decreasing acid strength. Identify the correct order.
$I$. $ClOH$
$II$. $BrOH$
$III$. $IOH$

In $s-$block,on moving down the group,the reactivity of metals with water and air increases. Which of the following factors has no significance for this trend of reactivity?