Question

Why is $Cs$ larger than $C{s}^{+}$?

• A. Electrons in $C{s}^{+}$ penetrate the nucleus more than $Cs$.
• B. There are fewer protons pulling the electrons towards the nucleus in $C{s}^{+}$ than $Cs$.
• C. Electrons in the orbitals repel more than electrons in the p orbitals.
• D. The valence electron in $Cs$ experiences more shielding than the valence electrons in $C{s}^{+}$.

Answer 1

The correct option is A Electrons in $C{s}^{+}$ penetrate the nucleus more than $Cs$.

The electrons and protons are same in 'Cs'. But in Cs${}^{+}$, protons are more than electrons. The protons attract more into the nucleus in Cs${}^{+}$ than 'Cs'. So Cs is larger than Cs${}^{+}$.