Question

First, second, third and fourth ionization enthalpies of an element are $579,1795,2758$ and $11580kJmo{l}^{-1}$ respectively, then stable state of element is:

• A. $+1$
• B. $+2$
• C. $+3$
• D. $+4$

Answer 1

Answer: (C)

$+3$

Observe the difference between the ionisation values of successive ionisation. Difference between $3^{rd}$ and $4^{th}$ ionisation value is very more. Means when it is in $+3$ state, it is more stable. So, more energy is required for further ionisation. So $4^{th}$ ionisation value is very more. So, stable state of element is $+3$ .