The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups. Why?

Which of the following sequences correctly represents the decreasing acidic nature of oxides?

Which of the following will liberate bromine from a potassium bromide solution?

In a periodic table, how does the basic character of oxides vary?

The first $\left( \Delta_{i}H_{1} \right)$ and the second $\left( \Delta_{i}H_{2} \right)$ ionization enthalpies (in $kJ \ mol^{-1}$) and the $\left( \Delta_{eg}H \right)$ electron gain enthalpy (in $kJ \ mol^{-1}$) of a few elements are given below:

Elements	$\left( \Delta_{i}H_{1} \right)$	$\left( \Delta_{i}H_{2} \right)$	$\left( \Delta_{eg}H \right)$
$I$	$520$	$7300$	$-60$
$II$	$419$	$3051$	$-48$
$III$	$1681$	$3374$	$-328$
$IV$	$1008$	$1846$	$-295$
$V$	$2372$	$8581$	$+48$
$VI$	$738$	$1451$	$-40$

Which of the above elements is likely to be:
$(a)$ the least reactive element.
$(b)$ the most reactive metal.
$(c)$ the most reactive non-metal.
$(d)$ the least reactive non-metal.
$(e)$ the metal which can form a stable binary halide of the formula $MX_{2}$ ($X =$ halogen).
$(f)$ the metal which can form a predominantly stable covalent halide of the formula $MX$ ($X =$ halogen)?

Which of the following sets has the strongest tendency to form anions?