In a group of elements,as the atomic number increases,which of the following is $NOT$ observed?

What do the processes $(i) X_{(g)} \to X^+_{(g)} + e^-$ and $(ii) X^+_{(g)} \to X^{2+}_{(g)} + e^-$ represent?

The first ionisation energies of alkaline earth metals are higher than those of the alkali metals. This is because

Given below are two statements:
Statement $I$: The decrease in first ionization enthalpy from $B$ to $Al$ is much larger than that from $Al$ to $Ga$.
Statement $II$: The $d$ orbitals in $Ga$ are completely filled.
In the light of the above statements,choose the most appropriate answer from the options given below:

The energy required to remove an electron of a gaseous atom from its ground state is called

The atomic numbers of elements $X, Y$,and $Z$ are $19, 37$,and $55$ respectively. Which of the following statements is correct?