Question

The elements which occupy the peaks of ionization energy curve, are

• A. Na, K, Rb, Cs
• B. Na, Mg, Cl, I
• C. Cl, Br, I, F
• D. He, Ne, Ar, Kr

Answer 1

The correct option is D

He, Ne, Ar, Kr

What is ionization energy?

The minimum amount of energy required to remove the most loosely bound electron from an isolated atom in the gaseous state is called ionization energy or enthalpy. Energies required to remove $2^{nd}$ - $3^{rd}$ $e^{-}$ are called successive ionization energy.

$\Rightarrow$ Nobel gases have fully filled orbitals and they are most stable.

So, it is very difficult to remove an electron from them.

So, they will be having the maximum first ionization energy.

Therefore, the peaks of ionization energy (I) curve will be occupied by noble gases.

Here the noble gases are He, Ne, Ar and Kr.