b$.$ a $2p$ electron in $O^{2-},F^{-},N{a}^{+}$and $M{g}^{2+}.$ Is the calculated value of $Z^{**}$ consistent with the

relative sizes of these ions?

c$.$ a $4s$ and a $3d$ electron of $Cu.$ Which type of electron is more likely to be lost when copper

forms a positive ion?

a $4f$ electron in $Ce,Pr,$ and $Nd.$ There is a decrease in size, commonly known as the

lanthanide contraction, with increasing atomic number in the lanthanides. Are your values of

$Z^{**}$ consistent with this trend?