## Chemistry: Molecular Approach (4th Edition)

The larger atom or ion is: a. $K$ b. $F^-$ c. $Cl^-$
a. Cations are smaller than the atoms from which they are formed. So, $K$ is larger. b. Anions are larger than the atoms from which they are formed. So, $F^-$ is larger. c. Both $Ca^{2+}$ and $Cl^-$ are isoelectronic, but $Cl^-$ has fewer protons than $Ca^{2+}$. This results in less pull on the electrons and a larger radius of $Cl^-$ , for it has a smaller number of electrons.