Question

$A,B,C$ are three elements with the atomic number $Z-1,Z,Z+1$ respectively. $B$ is an inert gas.Which out of the three has least value of ionization energy?

• A. $A$
• B. $B$
• C. $C$
• D. All of these

Answer 1

The correct option is C $C$

$17181⟶$ Group No.

Elements: $ABC$

atomic number: $Z-1ZZ+1$

$B$ is inert. (Group-18)

$C$ belonging to group $1$ elements with electronic configuration $n{s}^1$ will be having least $ionizationenergy\left(IE\right)$ as it tends to lose this single $e^{-}$ present in $s-$ subshell and to acquire a stable state.