Question

The atomic number of the element with highest ionization energy among the following is:

• A. $z=16$
• B. $z=14$
• C. $z=13$
• D. $z=15$

Answer 1

Answer: (D)

$z=15$

The atomic number of the element with highest ionization energy among the following is $z=15$. $1s^{2}2s^{2}2p^{6}3s^{2}3p^3$. $3p$ orbital is half filled it is stable. large amount of energy is required to break half-filled orbital.