Question

The removal of an electron is very difficult from:

• A. $Ar$ atom
• B. $C{l}^{-}$ ion
• C. $C{a}^{2+}$ ion
• D. $N{a}^{+}$ ion

Answer 1

The correct option is C $C{a}^{2+}$ ion

The removal of an electron from species is called ionization

Here,

$Ar$ has ${18e}^{-}$

${Cl}^{-}$ has ${18e}^{-}$

${Ca}^{2+}$ has ${18e}^{-}$

${Na}^{+}$ has ${10e}^{-}$

Here ${Na}^{+}$ size is less than the other, which means nuclear hold of the electrons will be more but it will be less compared to $C{a}^{2+}$ since it has 2 unit positive charge. Therefore removal of an electron will be difficult.