The chemical properties of $Li$ and $Mg$ are similar because:

Which group element from the following achieves noble gas configuration after gaining two electrons?

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

The periodic table consists of $18$ groups. An isotope of copper,on bombardment with protons,undergoes a nuclear reaction yielding element $X$ as shown below. To which group,element $X$ belongs in the periodic table?
${}_{29}^{83}Cu + {}_{1}^{1}H \rightarrow 6{}_{0}^{1}n + {}_{2}^{4}\alpha + 2{}_{1}^{1}H + X$

Similarity in chemical properties of the atoms of elements in a group of the Periodic table is most closely related to

Which of the following orders correctly represents the increasing acidic strength of the given acids?