Which ion, or , is attracted to a magnetic field? Give reasons. (Atomic Number of and )

$\text{Co}^{2+}$ is attracted to a magnetic field. Reason: $\text{Co}^{2+}$ ($Z = 27$) has the electronic configuration $[\text{Ar}] 3d^7$. In the $3d$ subshell, there are 3 unpaired electrons ($n = 3$), making the ion paramagnetic, so it is attracted to a magnetic field. In contrast, $\text{Zn}^{2+}$ ($Z = 30$) has the electronic configuration $[\text{Ar}] 3d^{10}$, in which all electrons are paired ($n = 0$), making it diamagnetic (repelled by a magnetic field).